importance of covid 19 vaccine research paper

• Scoping Review
• Open access
• Published: 14 November 2021

Effectiveness and safety of SARS-CoV-2 vaccine in real-world studies: a systematic review and meta-analysis

• Qiao Liu 1   na1 ,
• Chenyuan Qin 1 , 2   na1 ,
• Min Liu 1 &
• Jue Liu   ORCID: orcid.org/0000-0002-1938-9365 1 , 2  

Infectious Diseases of Poverty volume  10 , Article number:  132 ( 2021 ) Cite this article

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To date, coronavirus disease 2019 (COVID-19) becomes increasingly fierce due to the emergence of variants. Rapid herd immunity through vaccination is needed to block the mutation and prevent the emergence of variants that can completely escape the immune surveillance. We aimed to systematically evaluate the effectiveness and safety of COVID-19 vaccines in the real world and to establish a reliable evidence-based basis for the actual protective effect of the COVID-19 vaccines, especially in the ensuing waves of infections dominated by variants.

We searched PubMed, Embase and Web of Science from inception to July 22, 2021. Observational studies that examined the effectiveness and safety of SARS-CoV-2 vaccines among people vaccinated were included. Random-effects or fixed-effects models were used to estimate the pooled vaccine effectiveness (VE) and incidence rate of adverse events after vaccination, and their 95% confidence intervals ( CI ).

A total of 58 studies (32 studies for vaccine effectiveness and 26 studies for vaccine safety) were included. A single dose of vaccines was 41% (95% CI : 28–54%) effective at preventing SARS-CoV-2 infections, 52% (31–73%) for symptomatic COVID-19, 66% (50–81%) for hospitalization, 45% (42–49%) for Intensive Care Unit (ICU) admissions, and 53% (15–91%) for COVID-19-related death; and two doses were 85% (81–89%) effective at preventing SARS-CoV-2 infections, 97% (97–98%) for symptomatic COVID-19, 93% (89–96%) for hospitalization, 96% (93–98%) for ICU admissions, and 95% (92–98%) effective for COVID-19-related death, respectively. The pooled VE was 85% (80–91%) for the prevention of Alpha variant of SARS-CoV-2 infections, 75% (71–79%) for the Beta variant, 54% (35–74%) for the Gamma variant, and 74% (62–85%) for the Delta variant. The overall pooled incidence rate was 1.5% (1.4–1.6%) for adverse events, 0.4 (0.2–0.5) per 10 000 for severe adverse events, and 0.1 (0.1–0.2) per 10 000 for death after vaccination.

Conclusions

SARS-CoV-2 vaccines have reassuring safety and could effectively reduce the death, severe cases, symptomatic cases, and infections resulting from SARS-CoV-2 across the world. In the context of global pandemic and the continuous emergence of SARS-CoV-2 variants, accelerating vaccination and improving vaccination coverage is still the most important and urgent matter, and it is also the final means to end the pandemic.

Graphical Abstract

Since its outbreak, coronavirus disease 2019 (COVID-19) has spread rapidly, with a sharp rise in the accumulative number of infections worldwide. As of August 8, 2021, COVID-19 has already killed more than 4.2 million people and more than 203 million people were infected [ 1 ]. Given its alarming-spreading speed and the high cost of completely relying on non-pharmaceutical measures, we urgently need safe and effective vaccines to cover susceptible populations and restore people’s lives into the original [ 2 ].

According to global statistics, as of August 2, 2021, there are 326 candidate vaccines, 103 of which are in clinical trials, and 19 vaccines have been put into normal use, including 8 inactivated vaccines and 5 protein subunit vaccines, 2 RNA vaccines, as well as 4 non-replicating viral vector vaccines [ 3 ]. Our World in Data simultaneously reported that 27.3% of the world population has received at least one dose of a COVID-19 vaccine, and 13.8% is fully vaccinated [ 4 ].

To date, COVID-19 become increasingly fierce due to the emergence of variants [ 5 , 6 , 7 ]. Rapid herd immunity through vaccination is needed to block the mutation and prevent the emergence of variants that can completely escape the immune surveillance [ 6 , 8 ]. Several reviews systematically evaluated the effectiveness and/or safety of the three mainstream vaccines on the market (inactivated virus vaccines, RNA vaccines and viral vector vaccines) based on random clinical trials (RCT) yet [ 9 , 10 , 11 , 12 , 13 ].

In general, RNA vaccines are the most effective, followed by viral vector vaccines and inactivated virus vaccines [ 10 , 11 , 12 , 13 ]. The current safety of COVID-19 vaccines is acceptable for mass vaccination, but long-term monitoring of vaccine safety is needed, especially in older people with underlying conditions [ 9 , 10 , 11 , 12 , 13 ]. Inactivated vaccines had the lowest incidence of adverse events and the safety comparisons between mRNA vaccines and viral vectors were controversial [ 9 , 10 ].

RCTs usually conduct under a very demanding research circumstance, and tend to be highly consistent and limited in terms of population characteristics and experimental conditions. Actually, real-world studies differ significantly from RCTs in terms of study conditions and mass vaccination in real world requires taking into account factors, which are far more complex, such as widely heterogeneous populations, vaccine supply, willingness, medical accessibility, etc. Therefore, the real safety and effectiveness of vaccines turn out to be a major concern of international community. The results of a mass vaccination of CoronaVac in Chile demonstrated a protective effectiveness of 65.9% against the onset of COVID-19 after complete vaccination procedures [ 14 ], while the outcomes of phase 3 trials in Brazil and Turkey were 50.7% and 91.3%, reported on Sinovac’s website [ 14 ]. As for the Delta variant, the British claimed 88% protection after two doses of BNT162b2, compared with 67% for AZD1222 [ 15 ]. What is surprising is that the protection of BNT162b2 against infection in Israel is only 39% [ 16 ]. Several studies reported the effectiveness and safety of the COVID-19 vaccine in the real world recently, but the results remain controversial [ 17 , 18 , 19 , 20 ]. A comprehensive meta-analysis based upon the real-world studies is still in an urgent demand, especially for evaluating the effect of vaccines on variation strains. In the present study, we aimed to systematically evaluate the effectiveness and safety of the COVID-19 vaccine in the real world and to establish a reliable evidence-based basis for the actual protective effect of the COVID-19 vaccines, especially in the ensuing waves of infections dominated by variants.

Search strategy and selection criteria

Our methods were described in detail in our published protocol [PROSPERO (Prospective register of systematic reviews) registration, CRD42021267110]. We searched eligible studies published by 22 July 2021, from three databases including PubMed, Embase and Web of Science by the following search terms: (effectiveness OR safety) AND (COVID-19 OR coronavirus OR SARS-CoV-2) AND (vaccine OR vaccination). We used EndNoteX9.0 (Thomson ResearchSoft, Stanford, USA) to manage records, screen and exclude duplicates. This study was strictly performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

We included observational studies that examined the effectiveness and safety of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines among people vaccinated with SARS-CoV-2 vaccines. The following studies were excluded: (1) irrelevant to the subject of the meta-analysis, such as studies that did not use SARS-CoV-2 vaccination as the exposure; (2) insufficient data to calculate the rate for the prevention of COVID-19, the prevention of hospitalization, the prevention of admission to the ICU, the prevention of COVID-19-related death, or adverse events after vaccination; (3) duplicate studies or overlapping participants; (4) RCT studies, reviews, editorials, conference papers, case reports or animal experiments; and (5) studies that did not clarify the identification of COVID-19.

Studies were identified by two investigators (LQ and QCY) independently following the criteria above, while discrepancies reconciled by a third investigator (LJ).

Data extraction and quality assessment

The primary outcome was the effectiveness of SARS-CoV-2 vaccines. The following data were extracted independently by two investigators (LQ and QCY) from the selected studies: (1) basic information of the studies, including first author, publication year and study design; (2) characteristics of the study population, including sample sizes, age groups, setting or locations; (3) kinds of the SARS-CoV-2 vaccines; (4) outcomes for the effectiveness of SARS-CoV-2 vaccines: the number of laboratory-confirmed COVID-19, hospitalization for COVID-19, admission to the ICU for COVID-19, and COVID-19-related death; and (5) outcomes for the safety of SARS-CoV-2 vaccines: the number of adverse events after vaccination.

We evaluated the risk of bias using the Newcastle–Ottawa quality assessment scale for cohort studies and case–control studies [ 21 ]. and assess the methodological quality using the checklist recommended by Agency for Healthcare Research and Quality (AHRQ) [ 22 ]. Cohort studies and case–control studies were classified as having low (≥ 7 stars), moderate (5–6 stars), and high risk of bias (≤ 4 stars) with an overall quality score of 9 stars. For cross-sectional studies, we assigned each item of the AHRQ checklist a score of 1 (answered “yes”) or 0 (answered “no” or “unclear”), and summarized scores across items to generate an overall quality score that ranged from 0 to 11. Low, moderate, and high risk of bias were identified as having a score of 8–11, 4–7 and 0–3, respectively.

Two investigators (LQ and QCY) independently assessed study quality, with disagreements resolved by a third investigator (LJ).

Data synthesis and statistical analysis

We performed a meta-analysis to pool data from included studies and assess the effectiveness and safety of SARS-CoV-2 vaccines by clinical outcomes (rates of the prevention of COVID-19, the prevention of hospitalization, the prevention of admission to the ICU, the prevention of COVID-19-related death, and adverse events after vaccination). Random-effects or fixed-effects models were used to pool the rates and adjusted estimates across studies separately, based on the heterogeneity between estimates ( I 2 ). Fixed-effects models were used if I 2  ≤ 50%, which represented low to moderate heterogeneity and random-effects models were used if I 2  > 50%, representing substantial heterogeneity.

We conducted subgroup analyses to investigate the possible sources of heterogeneity by using vaccine kinds, vaccination status, sample size, and study population as grouping variables. We used the Q test to conduct subgroup comparisons and variables were considered significant between subgroups if the subgroup difference P value was less than 0.05. Publication bias was assessed by funnel plot and Egger’s regression test. We analyzed data using Stata version 16.0 (StataCorp, Texas, USA).

A total of 4844 records were searched from the three databases. 2484 duplicates were excluded. After reading titles and abstracts, we excluded 2264 reviews, RCT studies, duplicates and other studies meeting our exclude criteria. Among the 96 studies under full-text review, 41 studies were excluded (Fig.  1 ). Ultimately, with three grey literatures included, this final meta-analysis comprised 58 eligible studies, including 32 studies [ 14 , 15 , 17 , 18 , 19 , 20 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 ] for vaccine effectiveness and 26 studies [ 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 ] for vaccine safety. Characteristics of included studies are showed in Additional file 1 : Table S1, Additional file 2 : Table S2. The risk of bias of all studies we included was moderate or low.

Flowchart of the study selection

Vaccine effectiveness for different clinical outcomes of COVID-19

We separately reported the vaccine effectiveness (VE) by the first and second dose of vaccines, and conducted subgroup analysis by the days after the first or second dose (< 7 days, ≥ 7 days, ≥ 14 days, and ≥ 21 days; studies with no specific days were classified as 1 dose, 2 dose or ≥ 1 dose).

For the first dose of SARS-CoV-2 vaccines, the pooled VE was 41% (95% CI : 28–54%) for the prevention of SARS-CoV-2 infection, 52% (95% CI : 31–73%) for the prevention of symptomatic COVID-19, 66% (95% CI : 50–81%) for the prevention of hospital admissions, 45% (95% CI : 42–49%) for the prevention of ICU admissions, and 53% (95% CI : 15–91%) for the prevention of COVID-19-related death (Table 1 ). The subgroup, ≥ 21 days after the first dose, was found to have the highest VE in each clinical outcome of COVID-19, regardless of ≥ 1 dose group (Table 1 ).

For the second dose of SARS-CoV-2 vaccines, the pooled VE was 85% (95% CI : 81–89%) for the prevention of SARS-CoV-2 infection, 97% (95% CI : 97–98%) for the prevention of symptomatic COVID-19, 93% (95% CI: 89–96%) for the prevention of hospital admissions, 96% (95% CI : 93–98%) for the prevention of ICU admissions, and 95% (95% CI : 92–98%) for the prevention of COVID-19-related death (Table 1 ). VE was 94% (95% CI : 78–98%) in ≥ 21 days after the second dose for the prevention of SARS-CoV-2 infection, higher than other subgroups, regardless of 2 dose group (Table 1 ). For the prevention of symptomatic COVID-19, VE was also relatively higher in 21 days after the second dose (99%, 95% CI : 94–100%). Subgroups showed no statistically significant differences in the prevention of hospital admissions, ICU admissions and COVID-19-related death (subgroup difference P values were 0.991, 0.414, and 0.851, respectively).

Vaccine effectiveness for different variants of SARS-CoV-2 in fully vaccinated people

In the fully vaccinated groups (over 14 days after the second dose), the pooled VE was 85% (95% CI: 80–91%) for the prevention of Alpha variant of SARS-CoV-2 infection, 54% (95% CI : 35–74%) for the Gamma variant, and 74% (95% CI : 62–85%) for the Delta variant. There was only one study [ 23 ] focused on the Beta variant, which showed the VE was 75% (95% CI : 71–79%) for the prevention of the Beta variant of SARS-CoV-2 infection. BNT162b2 vaccine had the highest VE in each variant group; 92% (95% CI : 90–94%) for the Alpha variant, 62% (95% CI : 2–88%) for the Gamma variant, and 84% (95% CI : 75–92%) for the Delta variant (Fig.  2 ).

Forest plots for the vaccine effectiveness of SARS-CoV-2 vaccines in fully vaccinated populations. A Vaccine effectiveness against SARS-CoV-2 variants; B Vaccine effectiveness against SARS-CoV-2 with variants not mentioned. SARS-CoV-2 severe acute respiratory syndrome coronavirus 2, COVID-19 coronavirus disease 2019, CI confidence interval

For studies which had not mentioned the variant of SARS-CoV-2, the pooled VE was 86% (95% CI: 76–97%) for the prevention of SARS-CoV-2 infection in fully vaccinated people. mRNA-1273 vaccine had the highest pooled VE (97%, 95% CI: 93–100%, Fig.  2 ).

Safety of SARS-CoV-2 vaccines

As Table 2 showed, the incidence rate of adverse events varied widely among different studies. We conducted subgroup analysis by study population (general population, patients and healthcare workers), vaccine type (BNT162b2, mRNA-1273, CoronaVac, and et al.), and population size (< 1000, 1000–10 000, 10 000–100 000, and > 100 000). The overall pooled incidence rate was 1.5% (95% CI : 1.4–1.6%) for adverse events, 0.4 (95% CI : 0.2–0.5) per 10 000 for severe adverse events, and 0.1 (95% CI : 0.1–0.2) per 10 000 for death after vaccination. Incidence rate of adverse events was higher in healthcare workers (53.2%, 95% CI : 28.4–77.9%), AZD1222 vaccine group (79.6%, 95% CI : 60.8–98.3%), and < 1000 population size group (57.6%, 95% CI : 47.9–67.4%). Incidence rate of sever adverse events was higher in healthcare workers (127.2, 95% CI : 62.7–191.8, per 10 000), Gam-COVID-Vac vaccine group (175.7, 95% CI : 77.2–274.2, per 10 000), and 1000–10 000 population size group (336.6, 95% CI : 41.4–631.8, per 10 000). Incidence rate of death after vaccination was higher in patients (7.6, 95% CI : 0.0–32.2, per 10 000), BNT162b2 vaccine group (29.8, 95% CI : 0.0–71.2, per 10 000), and < 1000 population size group (29.8, 95% CI : 0.0–71.2, per 10 000). Subgroups of general population, vaccine type not mentioned, and > 100 000 population size had the lowest incidence rate of adverse events, severe adverse events, and death after vaccination.

Sensitivity analysis and publication bias

In the sensitivity analyses, VE for SARS-CoV-2 infections, symptomatic COVID-19 and COVID-19-related death got relatively lower when omitting over a single dose group of Maria et al.’s work [ 33 ]; when omitting ≥ 14 days after the first dose group and ≥ 14 days after the second dose group of Alejandro et al.’s work [ 14 ], VE for SARS-CoV-2 infections, hospitalization, ICU admission and COVID-19-related death got relatively higher; and VE for all clinical status of COVID-19 became lower when omitting ≥ 14 days after the second dose group of Eric et al.’s work [ 34 ]. Incidence rate of adverse events and severe adverse events got relatively higher when omitting China CDC’s data [ 74 ]. P values of Egger’s regression test for all the meta-analysis were more than 0.05, indicating that there might not be publication bias.

To our knowledge, this is a comprehensive systematic review and meta-analysis assessing the effectiveness and safety of SARS-CoV-2 vaccines based on real-world studies, reporting pooled VE for different variants of SARS-CoV-2 and incidence rate of adverse events. This meta-analysis comprised a total of 58 studies, including 32 studies for vaccine effectiveness and 26 studies for vaccine safety. We found that a single dose of SARS-CoV-2 vaccines was about 40–60% effective at preventing any clinical status of COVID-19 and that two doses were 85% or more effective. Although vaccines were not as effective against variants of SARS-CoV-2 as original virus, the vaccine effectiveness was still over 50% for fully vaccinated people. Normal adverse events were common, while the incidence of severe adverse events or even death was very low, providing reassurance to health care providers and to vaccine recipients and promote confidence in the safety of COVID-19 vaccines. Our findings strengthen and augment evidence from previous review [ 75 ], which confirmed the effectiveness of the BNT162b2 mRNA vaccine, and additionally reported the safety of SARS-CoV-2 vaccines, giving insight on the future of SARS-CoV-2 vaccine schedules.

Although most vaccines for the prevention of COVID-19 are two-dose vaccines, we found that the pooled VE of a single dose of SARS-CoV-2 vaccines was about 50%. Recent study showed that the T cell and antibody responses induced by a single dose of the BNT162b2 vaccine were comparable to those naturally infected with SARE-CoV-2 within weeks or months after infection [ 76 ]. Our findings could help to develop vaccination strategies under certain circumstances such as countries having a shortage of vaccines. In some countries, in order to administer the first dose to a larger population, the second dose was delayed for up to 12 weeks [ 77 ]. Some countries such as Canada had even decided to delay the second dose for 16 weeks [ 78 ]. However, due to a suboptimum immune response in those receiving only a single dose of a vaccine, such an approach had a chance to give rise to the emergence of variants of SARS-CoV-2 [ 79 ]. There remains a need for large clinical trials to assess the efficacy of a single-dose administration of two-dose vaccines and the risk of increasing the emergence of variants.

Two doses of SARS-CoV-2 vaccines were highly effective at preventing hospitalization, severe cases and deaths resulting from COVID-19, while the VE of different groups of days from the second vaccine dose showed no statistically significant differences. Our findings emphasized the importance of getting fully vaccinated, for the fact that most breakthrough infections were mild or asymptomatic. A recent study showed that the occurrence of breakthrough infections with SARS-CoV-2 in fully vaccinated populations was predictable with neutralizing antibody titers during the peri-infection period [ 80 ]. We also found getting fully vaccinated was at least 50% effective at preventing SARS-CoV-2 variants infections, despite reduced effectiveness compared with original virus; and BNT162b2 vaccine was found to have the highest VE in each variant group. Studies showed that the highly mutated variants were indicative of a form of rapid, multistage evolutionary jumps, which could preferentially occur in the milieu of partial immune control [ 81 , 82 ]. Therefore, immunocompromised patients should be prioritized for anti-COVID-19 immunization to mitigate persistent SARS-CoV-2 infections, during which multimutational SARS-CoV-2 variants could arise [ 83 ].

Recently, many countries, including Israel, the United States, China and the United Kingdom, have introduced a booster of COVID-19 vaccine, namely the third dose [ 84 , 85 , 86 , 87 ]. A study of Israel showed that among people vaccinated with BNT162b2 vaccine over 60 years, the risk of COVID-19 infection and severe illness in the non-booster group was 11.3 times (95% CI: 10.4–12.3) and 19.5 times (95% CI: 12.9–29.5) than the booster group, respectively [ 84 ]. Some studies have found that the third dose of Moderna, Pfizer-BioNTech, Oxford-AstraZeneca and Sinovac produced a spike in infection-blocking neutralizing antibodies when given a few months after the second dose [ 85 , 87 , 88 ]. In addition, the common adverse events associated with the third dose did not differ significantly from the symptoms of the first two doses, ranging from mild to moderate [ 85 ]. The overall incidence rate of local and systemic adverse events was 69% (57/97) and 20% (19/97) after receiving the third dose of BNT162b2 vaccine, respectively [ 88 ]. Results of a phase 3 clinical trial involving 306 people aged 18–55 years showed that adverse events after receiving a third dose of BNT162b2 vaccine (5–8 months after completion of two doses) were similar to those reported after receiving a second dose [ 85 ]. Based on V-safe, local reactions were more frequently after dose 3 (5323/6283; 84.7%) than dose 2 (5249/6283; 83.5%) among people who received 3 doses of Moderna. Systemic reactions were reported less frequently after dose 3 (4963/6283; 79.0%) than dose 2 (5105/6283; 81.3%) [ 86 ]. On August 4, WHO called for a halt to booster shots until at least the end of September to achieve an even distribution of the vaccine [ 89 ]. At this stage, the most important thing we should be thinking about is how to reach a global cover of people at risk with the first or second dose, rather than focusing on the third dose.

Based on real world studies, our results preliminarily showed that complete inoculation of COVID-19 vaccines was still effective against infection of variants, although the VE was generally diminished compared with the original virus. Particularly, the pooled VE was 54% (95% CI : 35–74%) for the Gamma variant, and 74% (95% CI : 62–85%) for the Delta variant. Since the wide spread of COVID-19, a number of variants have drawn extensive attention of international community, including Alpha variant (B.1.1.7), first identified in the United Kingdom; Beta variant (B.1.351) in South Africa; Gamma variant (P.1), initially appeared in Brazil; and the most infectious one to date, Delta variant (B.1.617.2) [ 90 ]. Israel recently reported a breakthrough infection of SARS-CoV-2, dominated by variant B.1.1.7 in a small number of fully vaccinated health care workers, raising concerns about the effectiveness of the original vaccine against those variants [ 80 ]. According to an observational cohort study in Qatar, VE of the BNT162b2 vaccine against the Alpha (B.1.1.7) and Beta (B.1.351) variants was 87% (95% CI : 81.8–90.7%) and 75.0% (95% CI : 70.5–7.9%), respectively [ 23 ]. Based on the National Immunization Management System of England, results from a recent real-world study of all the general population showed that the AZD1222 and BNT162b2 vaccines protected against symptomatic SARS-CoV-2 infection of Alpha variant with 74.5% (95% CI : 68.4–79.4%) and 93.7% (95% CI : 91.6–95.3%) [ 15 ]. In contrast, the VE against the Delta variant was 67.0% (95% CI : 61.3–71.8%) for two doses of AZD1222 vaccine and 88% (95% CI : 85.3–90.1%) for BNT162b2 vaccine [ 15 ].

In terms of adverse events after vaccination, the pooled incidence rate was very low, only 1.5% (95% CI : 1.4–1.6%). However, the prevalence of adverse events reported in large population (population size > 100 000) was much lower than that in small to medium population size. On the one hand, the vaccination population in the small to medium scale studies we included were mostly composed by health care workers, patients with specific diseases or the elderly. And these people are more concerned about their health and more sensitive to changes of themselves. But it remains to be proved whether patients or the elderly are more likely to have adverse events than the general. Mainstream vaccines currently on the market have maintained robust safety in specific populations such as cancer patients, organ transplant recipients, patients with rheumatic and musculoskeletal diseases, pregnant women and the elderly [ 54 , 91 , 92 , 93 , 94 ]. A prospective study by Tal Goshen-lag suggests that the safety of BNT162b2 vaccine in cancer patients is consistent with those previous reports [ 91 ]. In addition, the incidence rate of adverse events reported in the heart–lung transplant population is even lower than that in general population [ 95 ]. On the other hand, large scale studies at the national level are mostly based on national electronic health records or adverse event reporting systems, and it is likely that most mild or moderate symptoms are actually not reported.

Compared with the usual local adverse events (such as pain at the injection site, redness at the injection site, etc.) and normal systemic reactions (such as fatigue, myalgia, etc.), serious and life-threatening adverse events were rare due to our results. A meta-analysis based on RCTs only showed three cases of anaphylactic shock among 58 889 COVID-19 vaccine recipients and one in the placebo group [ 11 ]. The exact mechanisms underlying most of the adverse events are still unclear, accordingly we cannot establish a causal relation between severe adverse events and vaccination directly based on observational studies. In general, varying degrees of adverse events occur after different types of COVID-19 vaccination. Nevertheless, the benefits far outweigh the risks.

Our results showed the effectiveness and safety of different types of vaccines varied greatly. Regardless of SARS-CoV-2 variants, vaccine effectiveness varied from 66% (CoronaVac [ 14 ]) to 97% (mRNA-1273 [ 18 , 20 , 45 , 46 ]). The incidence rate of adverse events varied widely among different types of vaccines, which, however, could be explained by the sample size and population group of participants. BNT162b2, AZD1222, mRNA-1273 and CoronaVac were all found to have high vaccine efficacy and acceptable adverse-event profile in recent published studies [ 96 , 97 , 98 , 99 ]. A meta-analysis, focusing on the potential vaccine candidate which have reached to the phase 3 of clinical development, also found that although many of the vaccines caused more adverse events than the controls, most were mild, transient and manageable [ 100 ]. However, severe adverse events did occur, and there remains the need to implement a unified global surveillance system to monitor the adverse events of COVID-19 vaccines around the world [ 101 ]. A recent study employed a knowledge-based or rational strategy to perform a prioritization matrix of approved COVID-19 vaccines, and led to a scale with JANSSEN (Ad26.COV2.S) in the first place, and AZD1222, BNT162b2, and Sputnik V in second place, followed by BBIBP-CorV, CoronaVac and mRNA-1273 in third place [ 101 ]. Moreover, when deciding the priority of vaccines, the socioeconomic characteristics of each country should also be considered.

Our meta-analysis still has several limitations. First, we may include limited basic data on specific populations, as vaccination is slowly being promoted in populations under the age of 18 or over 60. Second, due to the limitation of the original real-world study, we did not conduct subgroup analysis based on more population characteristics, such as age. When analyzing the efficacy and safety of COVID-19 vaccine, we may have neglected the discussion on the heterogeneity from these sources. Third, most of the original studies only collected adverse events within 7 days after vaccination, which may limit the duration of follow-up for safety analysis.

Based on the real-world studies, SARS-CoV-2 vaccines have reassuring safety and could effectively reduce the death, severe cases, symptomatic cases, and infections resulting from SARS-CoV-2 across the world. In the context of global pandemic and the continuous emergence of SARS-CoV-2 variants, accelerating vaccination and improving vaccination coverage is still the most important and urgent matter, and it is also the final means to end the pandemic.

Availability of data and materials

All data generated or analyzed during this study are included in this published article and its additional information files.

Abbreviations

Coronavirus disease 2019

Severe Acute Respiratory Syndrome Coronavirus 2

Vaccine effectiveness

Confidence intervals

Intensive care unit

Random clinical trials

Preferred reporting items for systematic reviews and meta-analyses

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Acknowledgements

This study was funded by the National Natural Science Foundation of China (72122001; 71934002) and the National Science and Technology Key Projects on Prevention and Treatment of Major infectious disease of China (2020ZX10001002). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the paper. No payment was received by any of the co-authors for the preparation of this article.

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Department of Epidemiology and Biostatistics, School of Public Health, Peking University, Beijing, 100191, China

Qiao Liu, Chenyuan Qin, Min Liu & Jue Liu

Institute for Global Health and Development, Peking University, Beijing, 100871, China

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LQ and QCY contributed equally as first authors. LJ and LM contributed equally as correspondence authors. LJ and LM conceived and designed the study; LQ, QCY and LJ carried out the literature searches, extracted the data, and assessed the study quality; LQ and QCY performed the statistical analysis and wrote the manuscript; LJ, LM, LQ and QCY revised the manuscript. All authors read and approved the final manuscript.

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Supplementary Information

Additional file 1: table s1..

Characteristic of studies included for vaccine effectiveness.

Additional file 2: Table S2.

Characteristic of studies included for vaccine safety.

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Liu, Q., Qin, C., Liu, M. et al. Effectiveness and safety of SARS-CoV-2 vaccine in real-world studies: a systematic review and meta-analysis. Infect Dis Poverty 10 , 132 (2021). https://doi.org/10.1186/s40249-021-00915-3

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COVID-19 and vaccine hesitancy: A longitudinal study

Roles Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Project administration, Resources, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing

* E-mail: [email protected]

Affiliation Rady School of Management, University of California San Diego, La Jolla, California, United States of America

Roles Conceptualization, Data curation, Funding acquisition, Investigation, Methodology, Project administration, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing

Roles Conceptualization, Funding acquisition, Investigation, Methodology, Project administration, Supervision, Visualization, Writing – original draft, Writing – review & editing

• Ariel Fridman, 
• Rachel Gershon, 
• Ayelet Gneezy

• Published: April 16, 2021
• https://doi.org/10.1371/journal.pone.0250123
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How do attitudes toward vaccination change over the course of a public health crisis? We report results from a longitudinal survey of United States residents during six months (March 16 –August 16, 2020) of the COVID-19 pandemic. Contrary to past research suggesting that the increased salience of a disease threat should improve attitudes toward vaccines, we observed a decrease in intentions of getting a COVID-19 vaccine when one becomes available. We further found a decline in general vaccine attitudes and intentions of getting the influenza vaccine. Analyses of heterogeneity indicated that this decline is driven by participants who identify as Republicans, who showed a negative trend in vaccine attitudes and intentions, whereas Democrats remained largely stable. Consistent with research on risk perception and behavior, those with less favorable attitudes toward a COVID-19 vaccination also perceived the virus to be less threatening. We provide suggestive evidence that differential exposure to media channels and social networks could explain the observed asymmetric polarization between self-identified Democrats and Republicans.

Citation: Fridman A, Gershon R, Gneezy A (2021) COVID-19 and vaccine hesitancy: A longitudinal study. PLoS ONE 16(4): e0250123. https://doi.org/10.1371/journal.pone.0250123

Editor: Valerio Capraro, Middlesex University, UNITED KINGDOM

Received: November 12, 2020; Accepted: February 14, 2021; Published: April 16, 2021

Copyright: © 2021 Fridman et al. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All data and code are publicly available on the Open Science Framework at https://osf.io/kgvdy/ .

Funding: UC San Diego Global Health Initiative (GHI): awarded to all authors; Project number: 1001288. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. https://medschool.ucsd.edu/som/medicine/divisions/idgph/research/Global-Health/grant-recipients/2019-2020/Pages/Faculty-Postdoc-Travel-and-Research.aspx .

Competing interests: The authors have declared that no competing interests exist.

Introduction

Vaccinations are among the most important public health tools for reducing the spread and harm caused by dangerous diseases [ 1 ]. The World Health Organization estimates that vaccines prevented at least 10 million deaths between 2010–2015 worldwide [ 2 ]. Despite considerable evidence showing vaccines are safe [ 3 , 4 ], there is increasing skepticism toward vaccination [ 5 , 6 ]. Vaccine hesitancy has led to a decline in vaccine uptake and to an increase in the prevalence of vaccine-preventable diseases (VPDs) [ 7 , 8 ]. Ironically, the objection to vaccines is commonly a consequence of their effectiveness—because individuals have lower exposure to VPDs, they are less concerned about contracting them [ 9 ], which consequently leads to greater vaccine hesitancy [ 10 ]. The COVID-19 pandemic has created a new reality where individuals are faced with a previously unknown disease and its effects, providing a unique opportunity to investigate vaccine attitudes during a period of heightened disease salience. The present research reports findings from a longitudinal study conducted during the COVID-19 health crisis, in which we measured changes in attitudes toward a prospective vaccine, as well as shifts in vaccine attitudes in general.

Factors influencing vaccine attitudes and behaviors

Past research has identified a variety of situational and individual-level factors that influence vaccine attitudes and behavior, the most prominent of which are risk perceptions and demographic characteristics.

Assessments of risk are influenced by both cognitive evaluations (i.e., objective features of the situation such as probabilities of outcomes) and affective reactions [ 11 ], as well as by contextual factors (e.g., the information that is most available or salient at the time [ 12 ]). For example, research shows that media coverage plays a significant role in determining the extent to which we take threats seriously [ 13 ]. When individuals perceive heightened risk of a threat, they become more favorable toward interventions that mitigate that threat, including vaccination (for a meta-analysis on the effect of perceived risk on intentions and behaviors, see [ 14 ]). In the case of COVID-19, this would suggest more positive attitudes toward a vaccine and greater likelihood to get vaccinated. Indeed, research suggests that individuals should exhibit a greater interest in vaccinations during a pandemic because disease threat is more salient [ 15 ].

Past efforts to improve vaccine attitudes have had limited success or even backfired; for example, messages refuting claims about the link between vaccines and autism, as well as messages featuring images of children who were sick with VPDs, had negative effects on vaccine attitudes among those who were already hesitant to vaccinate [ 16 ]. In contrast, messaging that increases disease threat salience has shown promise in reducing vaccine hesitancy [ 5 ], and there is evidence suggesting that increased threat salience for a particular disease may also increase intentions to vaccinate for other diseases [ 17 ]. Building on these findings, we expected to find an increase in pro-vaccine attitudes and in individuals’ interest in a COVID-19 vaccine when the perceived threat of the COVID-19 virus increased.

Vaccine attitudes are also influenced by a variety of demographic and ideological factors (for a review, see [ 18 ]). For example, perceptions of vaccine risk differ among individuals of different ethnic backgrounds [ 19 ], and there is extant work demonstrating a positive correlation between socioeconomic status (SES) and vaccine hesitancy [ 20 , 21 ]. Socio-demographic factors are also linked to vaccine-related behaviors: among college students, those whose parents have attained a higher level of education are more likely to get immunized [ 22 ], and researchers have identified age as a predictor for receiving the influenza vaccine [ 23 ].

Political ideology is another well-documented determinant of vaccine-related attitudes and behaviors. Despite a common belief that liberals tend toward anti-vaccination attitudes in the United States, there is strong evidence that this trend is more present among conservatives [ 24 , 25 ]. According to a recent Gallup Poll, Republicans are twice as likely to believe the widely debunked myth that vaccines cause autism [ 26 ]. Recent work has shown that exposure to anti-vaccination tweets by President Trump—the first known U.S. president to publicly express anti-vaccination attitudes—has led to increased concern about vaccines among his supporters [ 27 ]. Based on these findings, and in conjunction with the sentiments expressed by the White House that diminished the significance of the pandemic [ 28 ], we expected to find diverging trends between Democrats and Republicans.

The current research

We collected vaccine-related attitudes of individuals living in the U.S. over a six-month period. Beginning in March 2020, we elicited attitudes from a cohort of the same individuals every month. We began data collection before any COVID-19 lockdown measures were in place (i.e., prior to the nation’s first shelter-in-place order [ 29 ]). Hence, our data spans the early phase of the pandemic, when there were fewer than 2,000 total confirmed cases in the U.S., through the following six months, at which point cumulative cases reached over 5.3 million [ 30 ].

Despite our prediction—that a public health crisis would increase disease threat, consequently increasing pro-vaccine attitudes and interest in vaccination—our data show an overall decrease in favorable attitudes toward vaccines. A closer look at the data revealed that political orientation explains more variance than any other socio-demographic variable. Specifically, participants who identify as Republican showed a decrease in their intention to get the COVID-19 vaccine and the influenza vaccine as well as a general decrease in pro-vaccine attitudes, whereas Democrats’ responses to these measures did not show a significant change during this period.

Our work is the first, to our knowledge, to longitudinally measure individuals’ attitudes toward vaccines. In doing so, our findings advance the understanding of how vaccine attitudes might change during an unprecedented public health crisis, revealing a strong association between political party affiliation and vaccine attitudes.

Participants

We recruited a panel of U.S. residents on Amazon’s Mechanical Turk platform to respond to multiple survey waves. To incentivize completion of all waves, we informed participants their payment would increase for subsequent surveys. Participants were paid 30 cents for wave 1, 40 cents for wave 2, and 60 cents for waves 3 and 4, $1.00 for wave 5, and $1.20 for wave 6. In addition, participants were informed that those who completed the first three waves would enter a $100 raffle. The median survey completion time was 5.5 minutes. The sample size for the first wave was 1,018, and the number of participants ranged from 608–762 on subsequent waves (see S1 Table for attrition details). This project was certified as exempt from IRB review by the University of California, San Diego Human Research Protections Program (Project #191273XX).

Our panel represents the broad and diverse population of the United States. The first wave sample included participants from all 50 states (except Wyoming) and Washington D.C., with an age range of 18 to 82 years old (mean = 38.48, median = 35). Approximately half (53%) identified as male, 46% as female, and.6% as other. The racial makeup in our sample was: 80% White, 9% Asian, 6% Black or African American, 4% multiple racial or ethnic identities, and 1% other. Relative to the U.S. Census (2019) [ 31 ] estimates, our sample over-represents White and Asian individuals, and under-represents Black or African American individuals and other racial groups.

We elicited political affiliation using a 6-point Likert scale, ranging from Strongly Republican to Strongly Democratic. In wave 1, 62% identified as Democrats and 38% identified as Republican, which is consistent with results from the most recent General Social Survey (GSS) [ 32 ]. There was no significant change in mean political identity from wave 1 to waves 2–6 (see S2 Table ). We classified participants as Democrats or Republicans using wave 1 political party affiliation. See S2 Appendix for additional details about the correlation of political party affiliation with age, gender, and SES.

Questions and measures

Our primary measure of interest was participants’ stated intention to get the COVID-19 vaccine when it becomes available. We were also interested in their perceptions of COVID-19 threat, general vaccination attitudes, and intention to get the flu shot. For all measures, except flu shot intentions, we combined multiple items to create a composite measure (see S2 Table for specific questions and construct compositions). Questions designed to measure general vaccination attitudes were adapted from prior work [ 33 ].

Additional measures of interest were participants’ trust in broad institutions (media, local government, and federal government). These trust measures followed different trends from each other, and therefore were not combined. At the end of the survey, participants responded to demographic questions. We retained all questions used in wave 1 throughout all six waves (our survey included additional items not reported in this paper; see S2 and S3 Tables for a complete list of measured items).

Data and analysis plan

Only participants with non-missing and non-duplicated responses were included in the analyses (see S1 Appendix for additional details). For all outcomes of interest, we tested for linear trends over time using a fixed effects regression specification [ 34 ]. All regression results include individual-level fixed effects, and standard errors are clustered at the individual level, to adjust for within-person correlation. We used this approach to control for the impact of omitted or unobserved time-invariant variables. P-values are not adjusted for multiple testing (see [ 35 ]). All analyses were conducted using R (version 4.0.2), and regressions were run using the package “fixest” (version 0.6.0). All materials, data, and additional analyses including robustness checks can be found here: https://osf.io/kgvdy/ .

We report results for three different vaccination-related measures: attitudes toward a COVID-19 vaccine, general vaccination attitudes, and flu shot intentions. All measures showed a decreasing trend (Ps < .001, except flu shot intentions where p = .05) for the 6-month duration of the study, indicating a reduction in pro-vaccination attitudes and intention to get vaccinated (COVID-19 and influenza vaccines). See S4 Table for full results of all regressions.

Heterogeneity in trend by political party

To better understand whether the decline in vaccine attitudes over time was driven by a particular factor, we used a data-driven approach, regressing all demographic characteristics on vaccine attitudes, in separate regressions. These demographics included education, income, SES, race, gender, an item measuring whether participants considered themselves to be a minority, whether the participant has children, and political party. Education, income, and SES were median split; race and gender were dummy coded; and political party affiliation was dichotomized into Democrat or Republican. Among all demographic characteristics, separating time trends by political affiliation (by adding an interaction term) attained the greatest adjusted within-R 2 in explaining vaccination attitude measures. In other words, political party affiliation explains the greatest within-individual variation in vaccine attitudes over time.

An analysis of responses by political affiliation revealed that the observed decreasing trend in all three vaccine measures was mostly driven by participants who identified as Republican (all Ps < .05), whereas Democrats’ responses showed either no significant trend (for COVID-19 vaccination and flu shot intentions: Ps >.67) or a significantly less negative time trend (general vaccination: p < .001). For these regressions, and moving forward, all results included interactions between wave and political party as well as interactions for wave and age, and wave and SES, to control for potentially different time trends associated with these variables. In each regression we also tested whether the strength of political affiliation moderates the observed results, and we reported the result when it did. We also conducted ANOVAs to compare mean responses for the outcomes of interest between Democrats and Republicans, separately for each wave (see S5 Table ).

COVID-19 vaccination attitudes ( Fig 1 , Panel A).

• PPT PowerPoint slide
• PNG larger image
• TIFF original image

Points represent means, and error bars represent 95% confidence intervals. All scale responses range from 1 to 7.

https://doi.org/10.1371/journal.pone.0250123.g001

A two-item construct ( r = .78) was created, with greater values corresponding to more favorable responses.

In wave 1, Democrats ( M = 5.39, SD = 1.55) had more favorable attitudes toward a COVID-19 vaccine than Republicans ( M = 4.57, SD = 1.76; t = -7.38, p < .001, d = -.48, 95% CI = [-.61, -.35]). Among Democrats, there was no significant time trend ( β = .02, SE = .04, p >.67) whereas Republicans’ responses followed a decreasing time trend ( β = -.09, SE = .05, p = .046). These trends were significantly different from each other ( β = -.11, SE = .02, p < .001).

General vaccination attitudes ( Fig 1 , Panel B).

A ten-item construct ( α = .95) was created, with greater values corresponding to a more positive attitude toward vaccination in general.

In wave 1, Democrats ( M = 5.83, SD = 1.15) expressed more favorable general vaccination attitudes than Republicans ( M = 5.17, SD = 1.31; t = -7.91, p < .001, d = -.52, 95% CI = [-.66, -.39]). Although both Democrats and Republicans had a decreasing time trend (Democrats: β = -.04, SE = .02, p = .029; Republicans: β = -.09, SE = .02, p < .001), the trend for Republicans was significantly more negative ( β = -.04, SE = .01, p < .001).

Flu shot intentions ( Fig 1 , Panel C).

We asked participants whether they plan to get the flu shot next year, with greater values indicating greater intentions.

In wave 1, Democrats ( M = 4.84, SD = 2.34) indicated greater intentions to vaccinate against the flu than Republicans ( M = 4.35, SD = 2.39; t = -3.15, p = .002, d = -.21, 95% CI = [-.34, -.08]). Among Democrats, there was no significant time trend ( β = .01, SE = .04, p = .86), suggesting their vaccination intentions remained largely stable. Republicans’ responses, however, revealed a decreasing time trend ( β = -.12, SE = .04, p = .005), and the two trends were significantly different from each other ( β = -.12, SE = .02, p < .001).

Our analyses revealed an interaction with political affiliation strength among Republicans, whereby participants who identified as more strongly Republican had a more negative time trend ( β = -.05, SE = .02, p = .027). This interaction was not significant for Democrats ( β = -.02, SE = .01, p = .19).

Perceived threat of COVID-19 ( Fig 2 ).

https://doi.org/10.1371/journal.pone.0250123.g002

A three-item construct ( α = .82) was created, with greater perceived threat about COVID-19.

In wave 1, Democrats ( M = 4.26, SD = 1.25) expressed greater perceived threat of COVID-19 than Republicans ( M = 3.90, SD = 1.39; t = -4.14, p < .001, d = -.40, 95% CI = [-.27, -.14]). Democrats’ responses showed an increasing time trend ( β = .08, SE = .04, p = .033), indicating they became increasingly concerned about the threat posed by the virus over time. Among Republicans, there was no significant time trend ( β = -.01, SE = .04, p = .83). These trends were significantly different from each other ( β = -.09, SE = .02, p < .001). While our data does not render causal claims, it is possible that the divergence in COVID-19 threat perceptions over time among Republicans and Democrats contributes to the divergence in vaccine attitudes between these groups over time. We revisit this proposition in the General Discussion.

Our analyses revealed an interaction with political affiliation strength among Democrats—participants who identified as more strongly Democrat had a more positive time trend ( β = .03, SE = .01, p = .019), suggesting an increasing threat perception over time. This interaction was not significant for Republicans ( β = .01, SE = .02, p = .61).

Trust in broad institutions.

The measures of trust in media, local government, and federal government were not highly correlated ( α = .66), and were therefore analyzed separately.

Trust in media ( Fig 3 , Panel A) . In wave 1, Democrats ( M = 3.61, SD = 1.66) reported greater trust in the media than Republicans ( M = 2.73, SD = 1.65; t = -8.12, p < .001, d = -.53, 95% CI = [-.66, -.39]). There was no significant time trend for either Democrats ( β = .02, SE = .04, p = .57) or Republicans ( β = -.05, SE = .04, p = .20). However, the trend for Republicans was significantly more negative ( β = -.07, SE = .02, p < .001). The different trends we observe for Democrats and Republicans with respect to trust in the media may explain the divergence in perceived threat and vaccine attitudes between these groups over time (see General discussion ).

https://doi.org/10.1371/journal.pone.0250123.g003

Trust in local government ( Fig 3 , Panel B) . In wave 1, Democrats ( M = 4.07, SD = 1.60) indicated lower trust in local government than Republicans ( M = 4.28, SD = 1.60; t = 2.01, p = .045, d = .13, 95% CI = [.003,.26]). Among Democrats, there was no significant time trend ( β = -.06, SE = .04, p = .18), though among Republicans, there was a decreasing time trend ( β = -.11, SE = .05, p = .015). These trends were significantly different from each other ( β = -.06, SE = .02, p = .004).

Trust in federal government ( Fig 3 , Panel C) . In wave 1, Democrats ( M = 2.96, SD = 1.67) expressed lower trust in the federal government than Republicans ( M = 4.08, SD = 1.60; t = 10.52, p < .001, d = .68, 95% CI = [.55,.82]). Both Democrats and Republicans had decreasing time trends (Democrats: β = -.08, SE = .04, p = .036; Republicans: β = -.10, SE = .04, p = .025). These trends were not significantly different from each other ( β = -.02, SE = .02, p = .37).

To rule out differential attrition, we tested whether the composition of our sample (i.e., age, gender, and political party) changed over time (see S1 Table ). Specifically, we tested whether participants who responded to waves 2–6 were significantly different at baseline (wave 1) from the full sample at baseline. The only significant change detected (Ps < .05) was with respect to participants’ age, though the differences were small—the average age was 38.5 at baseline, and remained between 39.9 and 40.8 at baseline among participants who responded to subsequent waves. We found no other systematic pattern of attrition among our participants.

General discussion

Over the course of six months of the COVID-19 pandemic, beginning with a relatively early phase prior to any U.S. directives to stay home (March 2020) and continuing through a cumulation of over 5 million cases (August 2020), we found a decrease in pro-vaccine attitudes and COVID-19 vaccination intentions, as well as reduced intentions to get the influenza vaccine. These findings are contrary to our prediction that increased salience of COVID-19 would improve attitudes toward vaccines.

Our analyses identify political ideology as the best predictor of the decreasing time trend across our three vaccine-related attitudes and intentions measures. In particular, we found that while Democrats’ responses remained fairly stable over time, Republicans shifted away from their lower initial responses and from Democrats’ responses, leading to increased polarization throughout the six-month period.

Contrary to the polarization observed in our data, social and behavioral scientists have long argued that groups facing threats often come together, demonstrating stronger social cohesion [ 36 ], and more cooperative behaviors [ 37 , 38 ]. Researchers have also found that individuals’ sense of shared identity plays a role in promoting cooperative behavior in response to threat [ 39 – 41 ]. Considering our results in the context of these findings might suggest that our respondents’ sense of shared identity was dominated by their political ideology, as opposed to a broader (e.g. American) identity.

What might be going on?

Although the nature of our data does not render causal claims, it highlights potential explanations. First, we note that participants’ ratings of perceived COVID-19 threat followed a similar diverging pattern by party affiliation to our three vaccine-related measures during the study period. Democrats perceived COVID-19 threat to be greater at the start of the study than Republicans did, and this gap widened significantly as the study progressed. This trend is consistent with previous research showing that vaccine hesitancy is related to perceived risk of a threat; when a VPD threat level is low, individuals are less motivated to take preventative action (i.e., immunize; for a review, see [ 42 ]).

Our data offers one potential explanation for the polarization of threat perception: Republican and Democratic participants in our study reported consuming different sources of information. The most commonly checked news source for Republicans was Fox News (Republicans: 50%, Democrats: 8%; χ 2 = 164.55, p < .001) and for Democrats was CNN (Democrats: 47%, Republicans: 23%, χ 2 = 43.08, p < .001, see S6 Table ). Corroborating this proposition, a Pew Research Center poll conducted in March 2020 found that 56% of respondents whose main news source is Fox News believed that “the news media have greatly exaggerated the risks about the Coronavirus outbreak,” whereas this was only true for 25% of those whose main news source is CNN [ 43 ]. Of note, Facebook and Instagram, were also in the top four most consumed news sources for participants affiliated with either party. Extant work describes these platforms as echo chambers [ 44 , 45 ], which may exacerbate partisan exposure to news and information.

Another trend highlighted by our data shows that similar to vaccine attitudes, Republicans’ trust in the media decreased significantly more during our study than Democrats’, suggesting these patterns might be related. According to Dr. Heidi Larson, an expert on vaccine hesitancy and founder of the Vaccine Confidence Project, misinformation regarding vaccinations is more likely to take root when individuals do not trust the information source [ 46 ]. Future research might further examine the role of trust in the media on vaccine attitudes.

While trust in media or media exposure may be driving COVID-19 threat perceptions and vaccine attitudes, there are many other possible explanatory factors that are not captured by our data or analyses. For example, it is possible that threat perceptions were influenced by how a respondents’ county or state was affected by COVID-19; up until June 2020, COVID-19 cases were more common in Democrat-leaning states [ 47 ], which might have amplified its salience early on and influenced attitudes and behavior. Further, although we included individual-level fixed-effects which control for all time invariant participant characteristics, and controlled for different trends by age and SES, we cannot rule out the possibility that other factors (e.g., educational attainment or population density) may have influenced the observed trends. Finally, as our data collection began after the onset of COVID-19, it is possible that the trend we observe for Republicans represents a return to a pre-pandemic baseline of vaccine-related attitudes.

Contributions

This work advances our understanding of how health-related attitudes evolve over time. Our focus on vaccine-related attitudes and intentions is important because experts agree that having enough people vaccinate against COVID-19 is key to stemming the pandemic [ 48 ]. More broadly, negative attitudes toward vaccination in general, and reduced vaccine uptake, is increasingly a public health concern [ 49 ]. This research provides insight into the trends of such vaccine hesitancy, underlining the importance of risk salience and its roots in ideology and media exposure.

This work also contributes to our understanding of political parties and polarization. Numerous anecdotes and reports have demonstrated a partisan divide in Americans’ response to the COVID-19 pandemic. For example, research found greater negative affective responses to wearing a face covering among politically right (vs. left) leaning individuals [ 50 ]. Here, we show that although these observations are valid, the reality is more nuanced. For example, our analyses reveal that polarization on vaccine measures—both attitudes and intentions—is driven primarily by self-identified Republicans’ gradual movement away from their initial responses whereas Democrats’ responses remained largely stable. This insight has important practical implications: It informs us about the dynamics of individuals’ attitudes, bringing us closer to understanding the underlying factors that influence attitudes and behaviors. Equipped with this knowledge, one could design more effective communications and interventions.

Note on methodology and data availability

The present study contributes to a small but growing literature in the social sciences using longitudinal data [ 51 ]. Using a longitudinal methodology allowed us to track individual-level changes over time. Merely observing a single point in time would allow us to observe across-group differences, but would lack the bigger picture of how polarization between these groups evolved. Another key advantage of panel data is that it allows us to include individual-level fixed effects, which control for the impact of omitted or unobserved time-invariant variables. Finally, panel data allows for more accurate inference of model parameters [ 52 ].

While the focus of this paper is vaccine attitudes, our broad dataset offers a unique opportunity to understand attitudes and behavior over time. Due to the richness of our data, its unique nature, and its timeliness, we believe it is important to make it available to other researchers interested in exploring it and publishing additional findings. The complete dataset is available at https://osf.io/kgvdy/ (see S2 and S3 Tables for all items collected).

Supporting information

S1 appendix. additional information about sample exclusions..

https://doi.org/10.1371/journal.pone.0250123.s001

S2 Appendix. Additional information about political party affiliation.

https://doi.org/10.1371/journal.pone.0250123.s002

S1 Table. Attrition table.

https://doi.org/10.1371/journal.pone.0250123.s003

S2 Table. Summary table of measures and constructs included in the text.

https://doi.org/10.1371/journal.pone.0250123.s004

S3 Table. Summary table of measures excluded from the text.

https://doi.org/10.1371/journal.pone.0250123.s005

S4 Table. Regression results.

https://doi.org/10.1371/journal.pone.0250123.s006

S5 Table. Outcome measures by political party affiliation.

https://doi.org/10.1371/journal.pone.0250123.s007

S6 Table. Summary of news sources.

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Ground-breaking study reveals how COVID-19 vaccines prevent severe disease

A landmark study by scientists at the University of Oxford, has unveiled crucial insights into the way that COVID-19 vaccines mitigate severe illness in those who have been vaccinated.

Despite the global success of COVID-19 vaccination campaigns, concerns remain around the continued spread of this disease including in vaccinated individuals. For this reason, researchers at the Oxford Vaccine Group conducted an extensive investigation into the human immune response to COVID-19, in both vaccinated and unvaccinated individuals.

Employing contemporary “big-data” analyses, scientists can find novel associations between fundamental biological entities and indicators of the severity of a disease — to build patterns of health and disease. Results of this study categorically show a reduction in indicators of disease severity in those who had received the vaccine, demonstrating that the harmful inflammatory reaction to COVID-19 is less severe in those who have been vaccinated, when compared with those who haven’t.

Professor Daniel O'Connor, Head of Bioinformatics at the Oxford Vaccine Group (OVG), led the study. He said: “These results confirm the efficacy of vaccination and its pivotal role in reducing the harmful consequences associated with COVID-19. The results of our research highlight the ChAdOx1 nCoV-19 vaccine's ability to modulate harmful responses to the SARS-CoV-2 virus, and therefore to reduce the severity of illness. The implications of these findings are far-reaching, offering evidence that is fundamental to future vaccine development and pandemic mitigation strategies. It also provides valuable guidance for policymakers and public health experts.”

Professor Sir Andrew Pollard, Ashall Professor of Infection and Immunity and Director of the Oxford Vaccine Group, said: “Better understanding of how vaccines can reduce the severity of infections caused by viruses like COVID-19 is a key part of our preparedness to make effective vaccines against the next pandemic threat. Ongoing research is critical as we know the next one is coming but we don’t know which virus or when it will be.”

The study employed state-of-the-art technologies, including RNA-sequencing (to capture the level of genes produced by blood cells), to achieve these results. While the findings are promising, the study acknowledges limitations such as a focus on mild cases and sample size constraints, highlighting the need for further research utilising advanced techniques to enhance resolution.

Key findings from the study include:

• Identification of unique responses to COVID-19 among vaccinated individuals, highlighting the vaccine's influence on responses to this disease.
• Demonstrated reduction in harmful responses associated with COVID-19 severity in recipients of the ChAdOx1 nCoV-19 vaccine compared with unvaccinated counterparts.
• COVID-19 in vaccinated individuals resulted in less COVID-19-induced blood cell count changes.
• Correlation between decreased levels of a particular class of molecules in blood (microRNAs) and elevated levels of inflammation, suggesting a regulatory role for these molecules in inflammatory responses to viral infection.

Funding for the study was provided by various organisations, including the National Institute for Health Research (NIHR), Oxford Biomedical Research Centre, and Oxford Nanopore Technologies. Notably, the ChAdOx1 nCoV-19 randomised controlled trials received support from UK Research and Innovation, NIHR, Coalition for Epidemic Preparedness Innovations, Bill & Melinda Gates Foundation, among others.

Notes for Editors

For media queries or to schedule interviews please contact Dr Adriaan Louis Taljaard, Manager Strategic Communications (Vaccines), Oxford University: [email protected] Link to the research paper: Multi-omics analysis reveals COVID-19 vaccine induced attenuation of inflammatory responses during breakthrough disease

About Oxford Vaccine Group (OVG) The Oxford Vaccine Group (OVG) designs and conducts studies of new and improved vaccines for children and adults around the world and is based in the Department of Paediatrics at the University of Oxford. Visit our website and follow us on X .

About the Department of Paediatrics The Department of Paediatrics is a world leader in child health research and hosts internationally renowned programmes in drug development, gastroenterology, haematology, HIV, immunology, neuroimaging, neuromuscular diseases and vaccinology. Its work spans from early proof-of-concept and fundamental science all the way up to its application in clinical settings. The Department aims to shape the landscape of medical science by positively impacting the lives of millions of children through its global research programmes, academic resources and commitment to success. With research facilities in the UK and abroad, the Department of Paediatrics works on an international scale, and has a strong, collaborative network with the medical science community across the globe.

About the University of Oxford Oxford University has been placed number 1 in the Times Higher Education World University Rankings for the eighth year running, and number 3 in the QS World Rankings 2024. At the heart of this success are the twin-pillars of our ground-breaking research and innovation and our distinctive educational offer. Oxford is world-famous for research and teaching excellence and home to some of the most talented people from across the globe. Our work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of our research alongside our personalised approach to teaching sparks imaginative and inventive insights and solutions. Through its research commercialisation arm, Oxford University Innovation, Oxford is the highest university patent filer in the UK and is ranked first in the UK for university spinouts, having created more than 300 new companies since 1988. Over a third of these companies have been created in the past five years. The university is a catalyst for prosperity in Oxfordshire and the United Kingdom, contributing £15.7 billion to the UK economy in 2018/19, and supports more than 28,000 full time jobs.

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A, Scatterplot and linear fit line for the relationship between time between last dose and delivery and maternal anti-S IgG levels by number of doses prior to delivery, stratified by preterm status. B, Scatterplot and linear fit line for the relationship between time between last dose and delivery and cord anti-S IgG levels by number of doses prior to delivery, stratified by preterm status. The horizontal dashed lines are the upper testing limit of the assay.

The horizontal lines in the boxes are the medians; upper and lower ends of the boxes indicate the 25th and 75th percentiles. Whiskers indicate all data points within 1.5 IQR of the upper and lower quartiles. Dots indicate outliers. The horizontal dashed lines indicate the upper testing limit of the assay.

eTable 1. Maternal and Cord Anti-Spike (S) Antibody Levels by Early Preterm, Late Preterm, and Term

eTable 2. Linear Regression Analyses of the Association Between Preterm Birth and Maternal and Cord Anti-Spike (S) Antibody Levels, Adjusted for Gestational Age at Last Dose, Time Between Last Dose and Delivery, and Number of Doses Prior to Delivery

eTable 3. Maternal and Cord Anti-Spike (S) Antibody Levels by Number of Doses During Pregnancy

eFigure . Scatterplot and Lowess Smoothing Line for the Relationship Between Time Between Last Dose and Delivery and Cord:Maternal Anti-Spike (S) Antibody Ratios by Preterm Status, Stratified by Number of Doses

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Kachikis A , Pike M , Eckert LO, et al. Timing of Maternal COVID-19 Vaccine and Antibody Concentrations in Infants Born Preterm. JAMA Netw Open. 2024;7(1):e2352387. doi:10.1001/jamanetworkopen.2023.52387

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Timing of Maternal COVID-19 Vaccine and Antibody Concentrations in Infants Born Preterm

• 1 Department of Obstetrics and Gynecology, University of Washington, Seattle
• 2 Department of Global Health, University of Washington, Seattle
• 3 Department of Obstetrics and Gynecology, University of California, San Diego
• 4 School of Medicine, Tel Aviv University, Tel Aviv, Israel
• 5 Department of Laboratory Medicine, University of Washington, Seattle
• 6 Seattle Children’s Hospital Research Institute, Department of Pediatrics, University of Washington, Seattle

Question   Does timing of COVID-19 vaccine administration affect maternally derived anti-Spike antibody concentrations in preterm compared with term infants?

Findings   Among 220 pregnancies in this cohort study, 36 pregnant participants (16.4%) delivered preterm infants before 37 weeks’ gestational age and 184 (83.6%) delivered at full term. After adjustment for timing of last vaccination dose, there was no difference in maternally derived anti-Spike IgG in preterm compared with full-term infants.

Meaning   These findings suggest that maternal anti-Spike antibody concentration is a key factor in determining preterm and full-term infant maternally derived anti-Spike concentrations.

Importance   COVID-19 vaccine–derived antibodies in pregnant people may protect infants from severe infection in the first 6 months of life via transplacental antibody transfer. Few data exist on maternally derived SARS-CoV-2 antibodies in preterm compared with full-term infants in association with vaccination timing.

Objective   To compare SARS-CoV-2 anti-Spike (anti-S) antibody levels in preterm and full-term infants in the context of vaccine dose timing before delivery.

Design, Setting, and Participants   This prospective cohort study enrolled pregnant individuals and collected paired maternal and cord blood samples at delivery at the University of Washington between February 1, 2021, and January 31, 2023. Participants who had received at least 2 doses of a messenger RNA COVID-19 vaccine before delivery and did not have a history of prior COVID-19 infection or detectable anti–SARS-CoV-2 nucleocapsid antibodies were included.

Exposures   Timing of the last vaccine dose and preterm or full-term gestational age at delivery.

Main Outcomes and Measures   Paired maternal and cord samples were tested for anti-S antibody, and linear regression was used to evaluate associations between preterm delivery and anti-S antibody levels. Covariates included timing of last dose, number of doses, insurance status, and immunosuppressing medications.

Results   A total of 220 participants (median [IQR] age, 34 [32-37] years; 212 [96.4%] female) with 36 preterm and 184 full-term deliveries were studied. Before delivery, 121 persons received 2 vaccine doses and 99 persons received 3 or more vaccine doses. The geometric mean concentration of maternal anti-S antibodies was 674 (95% CI, 577-787) after 2 doses and 8159 (95% CI, 6636-10 032) after 3 or more doses ( P  < .001). The cord anti-S antibody geometric mean concentration was 1000 (95% CI, 874-1144) after 2 doses and 9992 (95% CI, 8381-11 914) after 3 or more doses ( P  < .001). After adjustment for vaccine timing and number of doses before delivery, no association was found between preterm delivery and cord anti-S antibody levels (β = 0.44; 95% CI, −0.06 to 0.94).

Conclusions and Relevance   In this prospective cohort study of pregnant individuals with preterm and full-term deliveries, receipt of 3 or more compared with 2 doses of COVID-19 vaccine before delivery resulted in 10-fold higher cord anti-S antibody levels. Maternal antibody concentration appeared more important than delivery gestational age in determining cord anti-S antibody levels. The number of doses and timing considerations for COVID-19 vaccine in pregnancy should include individuals at risk for preterm delivery.

COVID-19 vaccines have been instrumental in decreasing morbidity and mortality from SARS-CoV-2 infection during pregnancy. 1 - 3 COVID-19 infection in pregnancy is associated with increased risk of hospitalization, intensive care unit admission, and mortality compared with nonpregnant individuals. 4 , 5 Studies 1 , 6 completed after the introduction of COVID-19 vaccines have shown that pregnant individuals who received vaccination have lower rates of maternal morbidity, hospital admission, critical care admission, stillbirth, and neonatal demise compared with pregnant individuals who were not vaccinated. COVID-19 vaccines induce anti-Spike (anti-S) antibody production in pregnant individuals that, similarly to antibodies against other respiratory infections, such as influenza, are able to cross the placenta via active transplacental antibody transfer. 7 COVID-19 vaccines given to pregnant persons may protect infants from severe COVID-19 illness via transplacental transfer of maternal IgG. 8 Few data exist on maternally derived SARS-CoV-2 antibody in infants born prematurely. Our objective was to evaluate anti-S antibody among paired maternal samples and cord samples from preterm and full-term deliveries.

Participants were recruited as part of an ongoing prospective cohort study on maternal immunizations in low- and high-risk pregnancies between February 1, 2021, and January 31, 2023. In the parent study, maternal and cord blood samples were collected at delivery after participants provided written informed consent. This study was approved by the University of Washington Human Subjects Division. The study followed the Strengthening the Reporting of Observational Studies in Epidemiology ( STROBE ) reporting guidelines. 9

Inclusion criteria for analysis were singleton pregnancy, receipt of 2 doses or more of messenger RNA (mRNA)–based COVID-19 vaccines before delivery, availability of paired maternal and cord samples, no history of prior COVID-19 infection, nondetectable antinucleocapsid (anti-N) antibody, no known fetal genetic anomaly, and infant birth weight appropriate for gestational age (>10th percentile) based on Olsen 2010 growth curves. 10 , 11 Participants were excluded from the analysis if they received 1 dose or less of a COVID-19 vaccine before delivery or received a non–mRNA-based vaccine.

Clinical data were abstracted from the electronic medical record, including linked Washington State Immunization Registry data, and entered into REDCap (Research Electronic Data Capture ) , version 12.1.1. Gender, race, and ethnicity data were collected to report diversity representation within our study population. Categorization of race and ethnicity followed Centers for Disease Control and Prevention’s National Health Interview Survey race and ethnicity categories. 12 Participants self-reported race and ethnic identity and gender during the registration process, which was entered into the electronic medical record. Information regarding demographics is collected at the time of registration or admission at University of Washington. Insurance status included public, private, Tricare (eg, military), federal, and other insurance. Body mass index was based on maternal weight at delivery and was calculated as weight in kilograms divided by height in meters squared. Pregestational diabetes included type 1 or 2 diabetes. We designated participants as having preeclampsia if they were diagnosed with preeclampsia with or without severe features, superimposed preeclampsia, or eclampsia according to American College of Obstetricians and Gynecologists’ criteria. 13 Participants had chronic hypertension if they were diagnosed with hypertension at less than 20 weeks’ gestational age. Participants with conditions such as systemic lupus erythematous or inflammatory bowel disease were designated as having autoimmune or inflammatory conditions. We considered participants taking immunosuppressing medications as those who received long-term corticosteroids, biologics, or other immunosuppressants. Evidence of SARS-CoV-2 infection was defined as a history of a positive COVID-19 test result by antigen or polymerase chain reaction or a positive anti-N serologic test result.

Participants included in this analysis received either 2 doses or 3 or more doses of mRNA COVID-19 vaccines before delivery and may have received between 0 and 4 doses during pregnancy. We calculated time from last vaccine dose to delivery date and gestational age at last vaccine dose in weeks. Complete data were available for gestational age at delivery, maternal and cord anti-S IgG, number of vaccine doses, timing of doses, and all covariates chosen for adjustment. The missingness in all other variables was less than 1%. No participants were lost to follow-up.

We tested paired maternal and cord samples collected at delivery for anti-S and anti-N antibody using Elecsys Anti-SARS-CoV-2 immunoassays (Roche Diagnostics) at the University of Washington virology laboratory. 14 This immunoassay is 99.5% sensitive and 99.8% specific for qualitative SARS-CoV-2 anti-N detection. 14 Results from the immunoassay for anti-S, a semiquantitative assay, and anti-N, a qualitative assay, were converted to geometric mean concentration (GMC) for final analysis. 15

Baseline characteristics are reported as absolute numbers and percentages or medians and IQRs. Comparison of baseline characteristics was performed using 2-tailed, unpaired t tests, χ 2 tests, and Fisher exact tests for subgroups with small numbers. We evaluated the association between preterm birth and maternal and cord anti-S antibody levels using linear regression analyses. We conducted similar analyses for cord anti-S antibody levels and cord to maternal anti-S antibody ratios, calculated from untransformed values of maternal and cord anti-S antibody levels. Cord to maternal antibody ratios of 1 or greater are generally considered to indicate efficient transplacental antibody transfer. 16 The cord to maternal anti-S antibody ratio was normally distributed and compared across the preterm group with 2-tailed, unpaired t tests. Anti-S antibody levels were log 2 transformed and reported as GMCs with 95% CIs. Covariates were chosen a priori and based on significant associations with the exposure of preterm birth and the outcomes of maternal and cord anti-S antibody. Minimally adjusted linear regression models included time between last dose and delivery (in weeks) and number of doses during pregnancy. Fully adjusted models additionally included insurance (private or other) and maternal use of immunosuppressing medications. A sensitivity analysis was completed with the inclusion of gestational age at last vaccination dose to the linear regression models. The first model included time between last dose and delivery, gestational age at last dose, and number of doses. The fully adjusted model additionally included insurance status and immunocompromising medications. Anti-S antibody levels, stratified by the number of vaccine doses before delivery, were also compared in full-term and preterm deliveries using the Wilcoxon rank sum tests for maternal and cord anti-S antibody and 2-tailed, unpaired t tests for cord to maternal antibody ratios. A sensitivity analysis was completed to examine maternal, cord, and cord to maternal anti-S antibody ratio between full-term and preterm deliveries based on the number of vaccine doses given during pregnancy. Wilcoxon rank sum tests and 2-tailed, unpaired t tests were used for the comparison of anti-S antibody levels. Statistical analysis was performed using Stata software, version 18.0 (StataCorp LLC). 17 A 2-sided P  < .05 was considered statistically significant.

A total of 220 participants met the inclusion criteria and had a median age of 34 years (IQR, 32-37 years), with a median gravidity of 2 (IQR, 1-3) and parity of 0 (IQR, 0-1). A total of 212 participants (96.4%) in our study identified as female, 1 (0.5%) identified as other gender, and 7 (3.2%) declined to answer. One participant (0.5%) identified as American Indian or Alaska Native, 26 (11.8%) as Asian, 5 (2.3%) as Black or African American, and 180 (81.8%) as White, with 8 (3.6%) declining to answer; 14 (6.4%) identified as Hispanic and 203 (92.3%) as non-Hispanic, with 3 (1.4%) declining to answer. Most participants (205 [93.2%]) had private insurance. There were 36 and 184 preterm and full-term deliveries, respectively. There were no differences in racial or ethnic identity or insurance status between participants with preterm or full-term delivery ( Table 1 ).

Participants with preterm delivery had a significantly higher median body mass index (preterm: 31.8 [IQR, 28.6-39.0]; full term: 29.7 [IQR, 27.1-33.2]; P  = .02), higher rates of pregestational diabetes (preterm: 5 [13.9%]; full term: 3 [1.6%]; P  < .004), preeclampsia (preterm: 15 [41.7%]; full term: 12 [6.5%]; P  < .001), and chronic hypertension (preterm: 7 [19.4%]; full term: 12 [6.5%]; P  = .02). There was no difference in autoimmune or inflammatory disease, receipt of immunosuppressing medications, or maternal total IgG concentrations between groups ( Table 1 ).

Preterm infants were delivered at a median gestational age of 35.1 weeks (IQR, 34.1-36.3 weeks), ranging from 27.9 to 36.9 weeks, whereas full-term infants were delivered at a median of 39.5 weeks (IQR, 38.7-40.3 weeks) ( P  < .001) ( Table 1 ). Of preterm deliveries, 7 (19.4%) delivered at less than 34 weeks’ gestational age. Pregnancies with preterm delivery were more likely to be delivered via cesarean section (preterm: 24 [66.7%]; full term: 64 [34.8%]; P  < .001), have lower median birth weight (preterm: 2437 g [IQR, 2049-2712 g]; full-term: 3453 g [IQR, 3180-3713]; P  < .001), and be admitted to the neonatal intensive care unit (preterm: 23 [63.9%]; full term: 10 [5.4%]; P  < .001).

Before delivery, 121 (55.0%) and 99 (45.0%) persons received 2 and 3 or more COVID-19 vaccine doses at any time (ie, before or during pregnancy), respectively. More participants with preterm delivery received 3 or more doses before delivery (preterm: 25 [69.4%]; full term: 74 [40.2%]) compared with 2 doses (preterm: 11 [30.6%]; full term: 110 [59.8%]; P  = .006). The number of vaccine doses during pregnancy also significantly differed between pregnancies with preterm and full-term deliveries, with 7 patients (19.4%) with preterm delivery receiving 2 doses compared with 114 participants (62.0%) with full-term delivery ( P  < .001). Median time between last vaccine dose and delivery was 16 weeks (IQR, 7-24 weeks); median gestational age at last dose was 25 weeks (IQR, 18-32 weeks), without difference between preterm and full-term pregnancies ( Table 1 ).

After 2 doses, the unadjusted maternal anti-S antibody GMC was 674 (95% CI, 577-787), and after 3 or more doses, the GMC was 8159 (95% CI, 6636-10 032) ( P  < .001). Unadjusted cord anti-S antibody GMC was 1000 (95% CI, 874-1144) and 9992 (95% CI, 8381-11 914) after 2 and 3 or more doses, respectively ( P  < .001) ( Table 2 , Figure 1 , and Figure 2 ). Overall, pregnancies with preterm deliveries had lower cord to maternal antibody ratios (preterm: 1.18 [95% CI, 1.02-1.38]; full term: 1.40 [95% CI, 1.31-1.49]; P  = .02) ( Table 2 ). Pregnancies delivered at less than 34 weeks’ gestational age had cord to maternal antibody ratios of 0.97 (95% CI, 0.57-1.66) compared with those delivered late preterm (ratio, 1.24; 95% CI, 1.06-1.45) and full term (ratio, 1.40; 95% CI, 1.31-1.49) ( P  = .34) (eTable 1 in Supplement 1 ).

We ran 2 separate linear regression analyses to adjust for vaccine dose timing and other covariates found to be associated with anti-S IgG concentration. In our first model, we adjusted for the number of COVID-19 vaccine doses during pregnancy and time between last vaccine dose and delivery. After adjustment in our first model, there was no association between preterm delivery and cord anti-S antibody levels (β = 0.46; 95% CI, −0.03 to 0.95). In our second model, we additionally adjusted for insurance status and immunosuppressing medication use. In this model, no significant difference between cord anti-S antibody levels was found between pregnancies with preterm and full-term deliveries (β = 0.44; 95% CI, −0.06 to 0.94). Maternal anti-S antibody levels were significantly higher and cord to maternal anti-S antibody ratios significantly lower in pregnancies with preterm deliveries compared with those with full-term deliveries ( Table 3 ).

We also ran a linear regression analysis to adjust for gestational age at last vaccine dose and other covariates associated with anti-S antibody concentration. For this analysis, 19 participants were excluded (8 with preterm deliveries and 11 with full-term deliveries) due to no vaccine dose during pregnancy. After adjustment in our first model, there was no significant association between preterm delivery and cord anti-S titers (β = 0.28; 95% CI, −0.31 to 0.87) (eTable 2 in Supplement 1 ). In our second model, additionally adjusted for insurance status and immunosuppressing medication use, there was also no significant difference between cord anti-S concentrations in pregnancies with preterm and full-term deliveries (β = 0.26; 95% CI, −0.34 to 0.86). Maternal anti-S antibody concentrations and cord to maternal anti-S antibody ratios were similar in pregnancies with preterm compared with full-term deliveries (eTable 2 in Supplement 1 ). In our sensitivity analysis examining anti-S antibody levels stratified by number of doses during pregnancy, maternal and cord anti-S antibody and cord to maternal ratios did not differ between preterm and full-term deliveries in pregnancies with 0 to 1 vaccine doses. In participants with 2 doses during pregnancy, maternal anti-S antibody levels, cord anti-S antibody levels, and cord to maternal antibody ratios differed between preterm and full-term deliveries (eTable 3 in Supplement 1 ). Cord to maternal antibody ratios peaked at approximately 10 weeks after last vaccine dose (eFigure in Supplement 1 ).

In this cohort study of COVID-19 vaccine among pregnancies with preterm and full-term deliveries, we found that, when adjusted for vaccine dose timing before delivery, cord anti-S antibody concentrations were similar in pregnancies with preterm compared with full-term deliveries. Furthermore, participants who had 3 or more doses of mRNA-based vaccines before delivery had significantly higher concentrations of maternal anti-S antibodies, resulting in 10-fold higher cord anti-S antibody levels. The finding that 3 or more doses of COVID-19 vaccine significantly enhance antibody concentrations compared with 2 doses has been reported in other observational pregnancy studies, 7 , 18 however, not in the comparison of preterm vs full-term infants. In nonpregnant adults, 3 or more doses of COVID-19 vaccine were less likely to be associated with symptomatic COVID-19 infection; this may be important for the pregnant population given the increased morbidity and mortality associated with COVID-19 illness in pregnancy. 19 Regarding potential infant protection, follow-up studies on infant morbidity with COVID-19 illness have been conducted among pregnant persons who received COVID-19 vaccine 8 , 20 ; however, these studies only evaluated pregnancies with 2 vaccine doses. Additional studies are currently being conducted to evaluate clinical outcomes among pregnant individuals and their infants after 3 COVID-19 vaccine doses. There is currently no clearly recognized immunologic correlate of protection for SARS-CoV-2, and transfer properties of antibodies generated by COVID-19 vaccines and SARS-CoV-2 antibodies in general may not be generalizable to other vaccines and other pathogen-specific antibodies. However, on the basis of the significantly enhanced antibody response after 3 or more vaccine doses, pregnant individuals should be encouraged to receive a booster before delivery. Individuals without known COVID-19 infection should be encouraged to receive the full COVID-19 vaccine series.

Maternally derived IgG antibody can be beneficial for premature infants given their higher risk for infection and adverse outcomes with infections in early life. Early studies on transplacental antibody transfer have shown that concentrations of maternal IgG increase steadily during gestation and that placental efficiency in transplacental IgG transfer is highly dependent on gestational age. 16 , 21 , 22 Concentrations of circulating fetal IgG increase from approximately 10% of the maternal concentration at 17 to 22 weeks to 50% at 28 to 32 weeks to greater than 100% of maternal antibody concentration at full term. 16 , 23 A cross-sectional study of 213 maternal-infant pairs by Okoko et al 24 from 2001 demonstrated lower antibody titers and transfer ratios in cord blood of infants born prematurely compared with full-term infants, but this was confounded by maternal malaria and uncertain timing of pathogen or vaccine exposure. More recently in 2014, van den Berg et al 25 found that cord to maternal IgG ratios for measles, mumps, rubella, and varicellaispecific antigens were significantly lower for preterm compared with full-term infants but that in preterm infants the influence of gestational age on maternally derived IgG levels in cord blood was less strong compared with the impact of maternal IgG concentrations. 25 Consistent with our findings, van den Berg et al 25 found that in preterm infants, the influence of gestational age on maternally derived IgG levels in cord blood was less strong compared with the impact of maternal IgG concentrations. 25 Although placental transfer ratios may be helpful in the context of gestational age to project potential concentrations of maternal IgG in the infant, our findings suggest that we may be able to improve potential infant immune protection by changing the framework of the discussion from transfer ratio to ultimate final concentration of maternally derived IgG in cord blood. If the focus is on maternal IgG titers in cord samples, this study and prior studies would suggest that pathogen-specific IgG concentrations in maternal blood must first be optimized to increase infant IgG concentrations. If maternal antibody concentrations are not boosted until the third trimester, many infants born prematurely will benefit less from maternal immunization.

The timing of vaccination during pregnancy is vital to maximize maternal antibody response as well as protection from severe COVID-19 illness and transplacental antibody transfer. Prior studies suggest waning maternal and cord anti-S antibody levels over time. In a prospective cohort study of 178 mother-infant pairs, Zilver et al 26 observed lower cord IgG levels at birth with greater time between last vaccine dose and delivery. Similarly, waning antibody concentrations were seen by Atyeo at al 27 in their prospective study of 123 maternal-neonatal dyads. Additional studies 28 , 29 found specifically that early third trimester vaccination results in higher IgG ratios, suggesting a buffer period before delivery is needed to boost maternal IgG concentrations and allow time for transplacental antibody transfer. Our data are consistent with prior studies showing a cord to maternal IgG ratio peak at approximately 10 weeks after vaccine dose. It is important to consider risk of waning maternal IgG concentrations while also emphasizing maternal protection from COVID-19 as well as targeting premature infants. Timing considerations for COVID-19 vaccine administration during pregnancy should consider individuals at risk for preterm delivery where mortality and morbidity are high.

This study has several strengths. We derived our study population from an institution with large numbers of both low- and high-risk pregnancies and selected our study participants based on stringent criteria, including receipt of mRNA-based vaccines only and no history or serologic evidence of prior COVID-19 infection based on negative test results for anti-N antibody. Hence, the concentrations of infant anti-S IgG in our study are derived solely from maternal immunization and not from prior COVID-19 infection. In addition, the Washington State Vaccination Registry provided the ability to obtain accurate vaccine data on our participants.

This study also has some limitations. Although our study is one of the largest on anti-S concentrations and vaccine timing in preterm and full-term deliveries, we were still limited by sample size and preterm deliveries that were confined to the third trimester (range, 27.9-36.9 weeks’ gestational age), and additional confounders may be present that we were not able to adjust for. Our selection criteria for this analysis based on at least 2 doses of mRNA-based vaccines before delivery may limit our population studied, as a prior study 29 found differences in COVID-19 vaccine acceptance among racial and ethnic groups. We also do not report results from neutralizing assays; however, a previous study 30 found a good correlation between anti-S antibody levels and neutralizing function. In addition, the Elecsys immunoassay has an upper limit of 25 720 BAU/mL, which was reached by 19 maternal and 19 cord samples in this study. The immunoassay also tests predominantly for IgG but may pick up small quantities of IgA and IgM. 12 Although characteristics of this immunoassay do not affect analyses of maternal and cord antibody concentrations, they may limit interpretation of cord to maternal antibody ratios.

Our data suggest that receipt of 2 or fewer COVID-19 vaccine doses may not provide optimal SARS-CoV-2 antibody titers and therefore protection for pregnant individuals and may not enable sufficient antibody transfer via cord blood for optimal infant protection, particularly in pregnant individuals who did not receive a primary COVID-19 vaccine series. As we note, our study excluded individuals with a history or serologic evidence of a prior COVID-19 infection, so we are not able to evaluate the impact of natural immunity from SARS-CoV-2 infection on infant antibody levels, and we acknowledge that an increasing proportion of the population has become infected with SARS-CoV-2. However, with the current primary COVID-19 vaccine series no longer available and a recent Advisory Committee on Immunization Practices recommendation for a single vaccine dose for all individuals, further study is warranted regarding COVID-19 vaccine dosing to provide optimal maternal and infant COVID-19 antibody protection. Finally, this study demonstrates that maternal anti-S antibody concentration is an important determinant of cord anti-S antibody levels. In individuals at risk for preterm delivery, timing of COVID-19 vaccine administration merits consideration.

Accepted for Publication: November 30, 2023.

Published: January 19, 2024. doi:10.1001/jamanetworkopen.2023.52387

Open Access: This is an open access article distributed under the terms of the CC-BY License . © 2024 Kachikis A et al. JAMA Network Open .

Corresponding Author: Alisa Kachikis, MD, MS, Department of Obstetrics and Gynecology, University of Washington, 1959 NE Pacific St, Box 356460, Seattle, WA 98195 ( [email protected] ).

Author Contributions: Drs Kachikis and Pike had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Kachikis, Eckert, Englund.

Acquisition, analysis, or interpretation of data: All authors.

Drafting of the manuscript: Kachikis, Roberts, Frank, Young, Englund.

Critical review of the manuscript for important intellectual content: Kachikis, Pike, Eckert, Goecker, Gravett, Greninger, Englund.

Statistical analysis: Pike.

Obtained funding: Kachikis.

Administrative, technical, or material support: Kachikis, Roberts, Frank, Young, Goecker, Gravett, Greninger, Englund.

Supervision: Kachikis, Eckert, Greninger, Englund.

Conflict of Interest Disclosures: Dr Kachikis reported working as an unpaid consultant for Pfizer and GlaxoSmithKline and as a coinvestigator for Merck and Pfizer outside the submitted work. Dr Greninger reported receiving grants from the Centers for Disease Control and Prevention during the conduct of the study and having central testing contracts with Abbott, Pfizer, Cepheid, Novavax, Janssen, and Hologic and receiving grants from Gilead outside the submitted work. Dr Englund reported receiving grants from University of Washington Support during the conduct of the study and grants from AstraZeneca, GlaxoSmithKline, Pfizer, and Merck, and personal fees from AbbVie, AstraZeneca, Meissa Vaccines, Moderna, Sanofi Pasteur, Pfizer, and Ark Biopharma outside the submitted work. No other disclosures were reported.

Funding/Support: This project was supported by grant K23 AI153390 from the National Institute of Allergy and Infectious Diseases (Dr Kachikis), a 2 K12HD001264-21 Women’s Reproductive Health Research Award (Dr Kachikis), the Thrasher Research Fund (Dr Kachikis), and award UL1 TR002319 from the National Center for Advancing Translational Sciences of the National Institutes of Health.

Role of the Funder/Sponsor: The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Disclaimer: The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Data Sharing Statement: See Supplement 2 .

Additional Contributions: We thank the participating individuals who contributed their valuable time and samples to this study. We also thank the clinical care practitioners from the University of Washington Medicine Center Montlake’s Labor and Delivery Unit and Northwest’s Childbirth Center who made this research possible.

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• Published: 16 June 2020

COVID-19 impact on research, lessons learned from COVID-19 research, implications for pediatric research

• Debra L. Weiner 1 , 2 ,
• Vivek Balasubramaniam 3 ,
• Shetal I. Shah 4 &
• Joyce R. Javier 5 , 6

on behalf of the Pediatric Policy Council

Pediatric Research volume  88 ,  pages 148–150 ( 2020 ) Cite this article

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The COVID-19 pandemic has resulted in unprecedented research worldwide. The impact on research in progress at the time of the pandemic, the importance and challenges of real-time pandemic research, and the importance of a pediatrician-scientist workforce are all highlighted by this epic pandemic. As we navigate through and beyond this pandemic, which will have a long-lasting impact on our world, including research and the biomedical research enterprise, it is important to recognize and address opportunities and strategies for, and challenges of research and strengthening the pediatrician-scientist workforce.

The first cases of what is now recognized as SARS-CoV-2 infection, termed COVID-19, were reported in Wuhan, China in December 2019 as cases of fatal pneumonia. By February 26, 2020, COVID-19 had been reported on all continents except Antarctica. As of May 4, 2020, 3.53 million cases and 248,169 deaths have been reported from 210 countries. 1

Impact of COVID-19 on ongoing research

The impact on research in progress prior to COVID-19 was rapid, dramatic, and no doubt will be long term. The pandemic curtailed most academic, industry, and government basic science and clinical research, or redirected research to COVID-19. Most clinical trials, except those testing life-saving therapies, have been paused, and most continuing trials are now closed to new enrollment. Ongoing clinical trials have been modified to enable home administration of treatment and virtual monitoring to minimize participant risk of COVID-19 infection, and to avoid diverting healthcare resources from pandemic response. In addition to short- and long-term patient impact, these research disruptions threaten the careers of physician-scientists, many of whom have had to shift efforts from research to patient care. To protect research in progress, as well as physician-scientist careers and the research workforce, ongoing support is critical. NIH ( https://grants.nih.gov/policy/natural-disasters/corona-virus.htm ), PCORI ( https://www.pcori.org/funding-opportunities/applicant-and-awardee-faqs-related-covid-19 ), and other funders acted swiftly to provide guidance on proposal submission and award management, and implement allowances that enable grant personnel to be paid and time lines to be relaxed. Research institutions have also implemented strategies to mitigate the long-term impact of research disruptions. Support throughout and beyond the pandemic to retain currently well-trained research personnel and research support teams, and to accommodate loss of research assets, including laboratory supplies and study participants, will be required to complete disrupted research and ultimately enable new research.

In the long term, it is likely that the pandemic will force reallocation of research dollars at the expense of research areas funded prior to the pandemic. It will be more important than ever for the pediatric research community to engage in discussion and decisions regarding prioritization of funding goals for dedicated pediatric research and meaningful inclusion of children in studies. The recently released 2020 National Institute of Child Health and Development (NICHD) strategic plan that engaged stakeholders, including scientists and patients, to shape the goals of the Institute, will require modification to best chart a path toward restoring normalcy within pediatric science.

COVID-19 research

This global pandemic once again highlights the importance of research, stable research infrastructure, and funding for public health emergency (PHE)/disaster preparedness, response, and resiliency. The stakes in this worldwide pandemic have never been higher as lives are lost, economies falter, and life has radically changed. Ultimate COVID-19 mitigation and crisis resolution is dependent on high-quality research aligned with top priority societal goals that yields trustworthy data and actionable information. While the highest priority goals are treatment and prevention, biomedical research also provides data critical to manage and restore economic and social welfare.

Scientific and technological knowledge and resources have never been greater and have been leveraged globally to perform COVID-19 research at warp speed. The number of studies related to COVID-19 increases daily, the scope and magnitude of engagement is stunning, and the extent of global collaboration unprecedented. On January 5, 2020, just weeks after the first cases of illness were reported, the genetic sequence, which identified the pathogen as a novel coronavirus, SARS-CoV-2, was released, providing information essential for identifying and developing treatments, vaccines, and diagnostics. As of May 3, 2020 1133 COVID-19 studies, including 148 related to hydroxychloroquine, 13 to remdesivir, 50 to vaccines, and 100 to diagnostic testing, were registered on ClinicalTrials.gov, and 980 different studies on the World Health Organization’s International Clinical Trials Registry Platform (WHO ICTRP), made possible, at least in part, by use of data libraries to inform development of antivirals, immunomodulators, antibody-based biologics, and vaccines. On April 7, 2020, the FDA launched the Coronavirus Treatment Acceleration Program (CTAP) ( https://www.fda.gov/drugs/coronavirus-covid-19-drugs/coronavirus-treatment-acceleration-program-ctap ). On April 17, 2020, NIH announced a partnership with industry to expedite vaccine development ( https://www.nih.gov/news-events/news-releases/nih-launch-public-private-partnership-speed-covid-19-vaccine-treatment-options ). As of May 1, 2020, remdesivir (Gilead), granted FDA emergency use authorization, is the only approved therapeutic for COVID-19. 2

The pandemic has intensified research challenges. In a rush for data already thousands of manuscripts, news reports, and blogs have been published, but to date, there is limited scientifically robust data. Some studies do not meet published clinical trial standards, which now include FDA’s COVID-19-specific standards, 3 , 4 , 5 and/or are published without peer review. Misinformation from studies diverts resources from development and testing of more promising therapeutic candidates and has endangered lives. Ibuprofen, initially reported as unsafe for patients with COVID-19, resulted in a shortage of acetaminophen, endangering individuals for whom ibuprofen is contraindicated. Hydroxychloroquine initially reported as potentially effective for treatment of COVID-19 resulted in shortages for patients with autoimmune diseases. Remdesivir, in rigorous trials, showed decrease in duration of COVID-19, with greater effect given early. 6 Given the limited availability and safety data, the use outside clinical trials is currently approved only for severe disease. Vaccines typically take 10–15 years to develop. As of May 3, 2020, of nearly 100 vaccines in development, 8 are in trial. Several vaccines are projected to have emergency approval within 12–18 months, possibly as early as the end of the year, 7 still an eternity for this pandemic, yet too soon for long-term effectiveness and safety data. Antibody testing, necessary for diagnosis, therapeutics, and vaccine testing, has presented some of the greatest research challenges, including validation, timing, availability and prioritization of testing, interpretation of test results, and appropriate patient and societal actions based on results. 8 Relaxing physical distancing without data regarding test validity, duration, and strength of immunity to different strains of COVID-19 could have catastrophic results. Understanding population differences and disparities, which have been further exposed during this pandemic, is critical for response and long-term pandemic recovery. The “Equitable Data Collection and Disclosure on COVID-19 Act” calls for the CDC (Centers for Disease Control and Prevention) and other HHS (United States Department of Health & Human Services) agencies to publicly release racial and demographic information ( https://bass.house.gov/sites/bass.house.gov/files/Equitable%20Data%20Collection%20and%20Dislosure%20on%20COVID19%20Act_FINAL.pdf )

Trusted sources of up-to-date, easily accessible information must be identified (e.g., WHO https://www.who.int/emergencies/diseases/novel-coronavirus-2019/global-research-on-novel-coronavirus-2019-ncov , CDC https://www.cdc.gov/coronavirus/2019-nCoV/hcp/index.html , and for children AAP (American Academy of Pediatrics) https://www.aappublications.org/cc/covid-19 ) and should comment on quality of data and provide strategies and crisis standards to guide clinical practice.

Long-term, lessons learned from research during this pandemic could benefit the research enterprise worldwide beyond the pandemic and during other PHE/disasters with strategies for balancing multiple novel approaches and high-quality, time-efficient, cost-effective research. This challenge, at least in part, can be met by appropriate study design, collaboration, patient registries, automated data collection, artificial intelligence, data sharing, and ongoing consideration of appropriate regulatory approval processes. In addition, research to develop and evaluate innovative strategies and technologies to improve access to care, management of health and disease, and quality, safety, and cost effectiveness of care could revolutionize healthcare and healthcare systems. During PHE/disasters, crisis standards for research should be considered along with ongoing and just-in-time PHE/disaster training for researchers willing to share information that could be leveraged at time of crisis. A dedicated funded core workforce of PHE/disaster researchers and funded infrastructure should be considered, potentially as a consortium of networks, that includes physician-scientists, basic scientists, social scientists, mental health providers, global health experts, epidemiologists, public health experts, engineers, information technology experts, economists and educators to strategize, consult, review, monitor, interpret studies, guide appropriate clinical use of data, and inform decisions regarding effective use of resources for PHE/disaster research.

Differences between adult and pediatric COVID-19, the need for pediatric research

As reported by the CDC, from February 12 to April 2, 2020, of 149,760 cases of confirmed COVID-19 in the United States, 2572 (1.7%) were children aged <18 years, similar to published rates in China. 9 Severe illness has been rare. Of 749 children for whom hospitalization data is available, 147 (20%) required hospitalization (5.7% of total children), and 15 of 147 required ICU care (2.0%, 0.58% of total). Of the 95 children aged <1 year, 59 (62%) were hospitalized, and 5 (5.3%) required ICU admission. Among children there were three deaths. Despite children being relatively spared by COVID-19, spread of disease by children, and consequences for their health and pediatric healthcare are potentially profound with immediate and long-term impact on all of society.

We have long been aware of the importance and value of pediatric research on children, and society. COVID-19 is no exception and highlights the imperative need for a pediatrician-scientist workforce. Understanding differences in epidemiology, susceptibility, manifestations, and treatment of COVID-19 in children can provide insights into this pathogen, pathogen–host interactions, pathophysiology, and host response for the entire population. Pediatric clinical registries of COVID-infected, COVID-exposed children can provide data and specimens for immediate and long-term research. Of the 1133 COVID-19 studies on ClinicalTrials.gov, 202 include children aged ≤17 years. Sixty-one of the 681 interventional trials include children. With less diagnostic testing and less pediatric research, we not only endanger children, but also adults by not identifying infected children and limiting spread by children.

Pediatric considerations and challenges related to treatment and vaccine research for COVID-19 include appropriate dosing, pediatric formulation, and pediatric specific short- and long-term effectiveness and safety. Typically, initial clinical trials exclude children until safety has been established in adults. But with time of the essence, deferring pediatric research risks the health of children, particularly those with special needs. Considerations specific to pregnant women, fetuses, and neonates must also be addressed. Childhood mental health in this demographic, already struggling with a mental health pandemic prior to COVID-19, is now further challenged by social disruption, food and housing insecurity, loss of loved ones, isolation from friends and family, and exposure to an infodemic of pandemic-related information. Interestingly, at present mental health visits along with all visits to pediatric emergency departments across the United States are dramatically decreased. Understanding factors that mitigate and worsen psychiatric symptoms should be a focus of research, and ideally will result in strategies for prevention and management in the long term, including beyond this pandemic. Social well-being of children must also be studied. Experts note that the pandemic is a perfect storm for child maltreatment given that vulnerable families are now socially isolated, facing unemployment, and stressed, and that children are not under the watch of mandated reporters in schools, daycare, and primary care. 10 Many states have observed a decrease in child abuse reports and an increase in severity of emergency department abuse cases. In the short term and long term, it will be important to study the impact of access to care, missed care, and disrupted education during COVID-19 on physical and cognitive development.

Training and supporting pediatrician-scientists, such as through NIH physician-scientist research training and career development programs ( https://researchtraining.nih.gov/infographics/physician-scientist ) at all stages of career, as well as fostering research for fellows, residents, and medical students willing to dedicate their research career to, or at least understand implications of their research for, PHE/disasters is important for having an ongoing, as well as a just-in-time surge pediatric-focused PHE/disaster workforce. In addition to including pediatric experts in collaborations and consortiums with broader population focus, consideration should be given to pediatric-focused multi-institutional, academic, industry, and/or government consortiums with infrastructure and ongoing funding for virtual training programs, research teams, and multidisciplinary oversight.

The impact of the COVID-19 pandemic on research and research in response to the pandemic once again highlights the importance of research, challenges of research particularly during PHE/disasters, and opportunities and resources for making research more efficient and cost effective. New paradigms and models for research will hopefully emerge from this pandemic. The importance of building sustained PHE/disaster research infrastructure and a research workforce that includes training and funding for pediatrician-scientists and integrates the pediatrician research workforce into high-quality research across demographics, supports the pediatrician-scientist workforce and pipeline, and benefits society.

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Department of Pediatrics, Division of Emergency Medicine, Boston Children’s Hospital, Boston, MA, USA

Debra L. Weiner

Harvard Medical School, Boston, MA, USA

Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA

Vivek Balasubramaniam

Department of Pediatrics and Division of Neonatology, Maria Fareri Children’s Hospital at Westchester Medical Center, New York Medical College, Valhalla, NY, USA

Shetal I. Shah

Division of General Pediatrics, Children’s Hospital Los Angeles, Los Angeles, CA, USA

Joyce R. Javier

Keck School of Medicine, University of Southern California, Los Angeles, CA, USA

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All authors made substantial contributions to conception and design, data acquisition and interpretation, drafting the manuscript, and providing critical revisions. All authors approve this final version of the manuscript.

Pediatric Policy Council

Scott C. Denne, MD, Chair, Pediatric Policy Council; Mona Patel, MD, Representative to the PPC from the Academic Pediatric Association; Jean L. Raphael, MD, MPH, Representative to the PPC from the Academic Pediatric Association; Jonathan Davis, MD, Representative to the PPC from the American Pediatric Society; DeWayne Pursley, MD, MPH, Representative to the PPC from the American Pediatric Society; Tina Cheng, MD, MPH, Representative to the PPC from the Association of Medical School Pediatric Department Chairs; Michael Artman, MD, Representative to the PPC from the Association of Medical School Pediatric Department Chairs; Shetal Shah, MD, Representative to the PPC from the Society for Pediatric Research; Joyce Javier, MD, MPH, MS, Representative to the PPC from the Society for Pediatric Research.

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Weiner, D.L., Balasubramaniam, V., Shah, S.I. et al. COVID-19 impact on research, lessons learned from COVID-19 research, implications for pediatric research. Pediatr Res 88 , 148–150 (2020). https://doi.org/10.1038/s41390-020-1006-3

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Issue Date : August 2020

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COVID-19 Vaccination Public Education Campaign Saved Thousands of Lives, Billions of Dollars

Study found vaccine campaign saved $90 for every $1 spent 

The U.S. Department of Health and Human Services’ (HHS) COVID-19 Vaccination Public Education Campaign, We Can Do This, resulted in an estimated$731.9 billion in societal benefits due to averted illness and related costs, resulting in a nearly $90 return in societal benefits for every $1 spent, according to research published today in the American Journal of Preventive Medicine .

“At the height of the pandemic, we launched one of the largest public health education campaigns in U.S. history to encourage and educate Americans on the steps they could take to get and stay healthy. We now have research to confirm the COVID-19 Public Education Campaign, We Can Do This, was an indispensable part of efforts to vaccinate people and protect them from COVID-19, saving thousands of lives and billions of dollars in the process,” said HHS Secretary Xavier Becerra. “HHS is responsible for protecting the health and well-being of all Americans. As stewards of the public’s money, we wanted to deliver impact for the American people in the most efficient and effective ways. This confirms we did exactly that. We will no doubt use what we learned in this campaign to further improve our public health efforts in the future.”

The study showed the Campaign encouraged 22.3 million people to complete their primary COVID-19 vaccination series between April 2021 and March 2022, preventing nearly 2.6 million SARS-CoV-2 infections, the virus that causes COVID-19, including nearly 244,000 hospitalizations, during the time period that the highly contagious Delta and Omicron virus variants were spreading.

Preventing these outcomes resulted in societal benefits to the U.S. of $740.2 billion, accounting for such factors as medical expenses, wages, and other costs that people and institutions would have incurred in the absence of the Campaign. In comparison, the Campaign cost $377 million, with an additional $7.9 billion spent to vaccinate 22.3 million people in that time period.

According to the study, from April 2021 to March 2022, the net benefit of the Campaign—how much money these efforts saved minus how much they cost—came to $731.9 billion, translating to a return on investment of $89.54 for every $1 spent.

In April 2021, HHS launched the We Can Do This Public Education Campaign to increase COVID-19 vaccine confidence and uptake in the U.S. The Campaign, one of the largest public health education efforts in U.S. history, promoted COVID-19 vaccine uptake using integrated, multichannel, research-based strategies. It aimed to reach 90% of adults in the United States at least once per quarter, with even more intense outreach to high-risk communities. The Campaign featured more than 7,000 ads in 14 languages, with many culturally tailored and geographically targeted to specific minority, racial, and ethnic audiences. A multimedia approach bolstered widespread engagement with trusted messengers, partner organizations, and influencers who delivered persuasive, accurate, and culturally relevant information to vaccine-hesitant populations.

The benefit-cost study of We Can Do This is the only research study to date that looked at the contributions of a media campaign to encourage people to get COVID-19 vaccines during the pandemic emergency period. The newly published study is unique in that it demonstrates that the nationwide media Campaign was an indispensable component of the nation’s efforts to vaccinate people and protect them from COVID-19. It also adds to the body of evidence that shows the Campaign’s impact on behavior change.

“This research confirms the benefits of public health campaigns as part of a multi-layered response to a public health crisis and to the effort to provide accurate information to the American public,” said May Malik, Senior Advisor for Public Education Campaigns at HHS.

To evaluate the benefits and costs of the national Campaign, researchers used real-world data from multiple sources, such as data on COVID-19 outcomes, uptake of COVID-19 vaccines, and vaccine effectiveness, from the U.S. Centers for Disease Control and Prevention (CDC), along with survey data collected to measure the Campaign’s effects on vaccination behaviors over time.

The findings can help inform the Federal response to future public health threats. As part of a multipronged approach to addressing public health crises, this study demonstrates the return on investment possible from public education campaigns given their effectiveness in building vaccine confidence and supporting healthy behavior change.

The study, Benefit-Cost Analysis of the HHS COVID-19 Campaign: April 2021–March 2022 , was conducted by researchers from HHS Office of the Assistant Secretary for Public Affairs and Fors Marsh in Arlington, Virginia.

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Original research article, older adults' experiences of wellbeing during the covid-19 pandemic: a comparative qualitative study in italy and switzerland.

• 1 Faculty of Social Sciences, University of Geneva, Geneva, Switzerland
• 2 Swiss Center of Expertise in Life Course Research (LIVES), Geneva, Switzerland
• 3 Faculty of Social Work, University of Applied Sciences and Arts Western Switzerland (HETSL/HES-SO), Lausanne, Switzerland

Background: Particularly at the beginning of the pandemic, adults aged 65 and older were portrayed as a homogeneously vulnerable population due to the elevated health risks associated with contracting the COVID-19 disease. This portrayal, combined with travel restrictions, closures of economic sectors, country-wide lockdowns, and suggestions by governmental authorities to limit social contact, had important implications for the wellbeing of older individuals. However, older adults are a heterogeneous population who relies on different resources to cope with stressful periods, like the COVID-19 pandemic. Simultaneously, countries also employed different measures to contain the virus. Research thus far has focused on the short-term consequences of the pandemic, but studies have yet to address its long-term consequences.

Objectives: We explore older adults' lived experiences nearly 2 years after the pandemic onset. Moreover, we focus on the bordering countries of Switzerland and Italy, who employed contrasting containment measures. This paper analyzes (1) How the COVID-19 pandemic impacted the experiences of wellbeing of older adults in these regions and (2) How older adults coped with the stressors brought about by the pandemic, in particular social distancing.

Methods: The paper draws on 31 semi-structured interviews with 11 Swiss natives residing in Switzerland, 10 Italian migrants residing in Switzerland, and 10 Italian natives residing in Italy. Interviews were conducted from December 2021 to March 2022.

Results: Coping mechanisms of the three groups related to acceptance, hobbies, cognitive reframing, telephone use, vaccine use and social distancing. However, results show heterogeneous experiences of wellbeing, with Swiss natives sharing more positive narratives than the other two groups. Moreover, Italian migrants and Italian natives expressed the long-term negative consequences of the pandemic on their experienced wellbeing.

1 Introduction

In March of 2020, the WHO declared COVID-19 a pandemic, making it an international public health problem ( WHO, 2020 ). Beyond physical illness, the pandemic disrupted millions of lives around the globe through closures of schools, shops, and borders; it separated individuals from friends and family, and it caused job losses and financial strain ( Hiscott et al., 2020 ). However, in the public discourse it was especially older adults who were portrayed as a homogeneously vulnerable and frail group ( Jordan et al., 2020 ; Ayalon et al., 2021 ; Maggiori et al., 2022 ). Indeed, older people had higher mortality rates than younger ones ( Dadras et al., 2022 ). They also suffered from decreased physical activity due to social distancing measures, impacting their physical health ( Oliveira et al., 2022 ). Moreover, in comparison to pre-pandemic levels, older adults reported higher rates of anxiety and depression ( Webb and Chen, 2022 ; Segerstrom et al., 2023 ) and lower subjective wellbeing ( Maggiori et al., 2022 ).

However, compared to their younger counterparts, older adults also reported less pandemic-related stress, less social isolation, less life changes ( Birditt et al., 2021 ), and lower rates of anxiety and depression ( Webb and Chen, 2022 ). Furthermore, older adults' resilience was shown through their ability to develop coping strategies to maintain a certain level of subjective and psychological wellbeing ( Finlay et al., 2021 ; Fuller and Huseth-Zosel, 2021 ; Bustamante et al., 2022 ; Facal et al., 2022 ; Mau et al., 2022 ).

Nonetheless, the ability to cope with the stressors brought about by the pandemic was influenced by factors on the micro-, meso-, and macro- levels. On the micro-level, studies have revealed that characteristics like being in good health, previous experiences of adversity, stable financial status, and social networks positively affected individuals' ability to cope with the pandemic ( Guzman et al., 2023 ), while having a migration background was associated with increased pandemic-related worry ( Ludwig-Dehm et al., 2023 ) and loneliness ( Pan et al., 2021 ). At the meso-level, neighborhood parks and nature were positively related to mental and physical health ( Bustamante et al., 2022 ; Guzman et al., 2023 ). At the macro-level, stricter physical distancing measures mandated by governments were associated with worse mental health ( Mendez-Lopez et al., 2022 ). The heterogeneity of older adults' characteristics, resources, and lived experiences, as well as the differences in countries' containment measures thus call for research further exploring how older adults coped with the pandemic in different contexts.

Most studies to date focus on older individuals' wellbeing during the first lockdown in the spring of 2020 ( Seifert and Hassler, 2020 ; Cipolletta and Gris, 2021 ; Falvo et al., 2021 ; Finlay et al., 2021 ; Fuller and Huseth-Zosel, 2021 ; McKinlay et al., 2021 ; Whitehead and Torossian, 2021 ; Bustamante et al., 2022 ; Facal et al., 2022 ; Gonçalves et al., 2022 ; Kremers et al., 2022 ) or during the first year following the pandemic onset ( Fiocco et al., 2021 ; Atzendorf and Gruber, 2022 ; Brooks et al., 2022 ; Cohn-Schwartz et al., 2022 ; Derrer-Merk et al., 2022a ; Garner et al., 2022 ; Maggiori et al., 2022 ; Mau et al., 2022 ; Donizzetti and Capone, 2023 ). However, few studies have been published thus far addressing the second year of the pandemic and its long-term impact on older adults' wellbeing ( Gallè et al., 2021 ; König and Isengard, 2023 ). Moreover, studies have analyzed the pandemic's impact on the physical health of migrants of all ages in comparison to native-born populations in Western Europe ( Canevelli et al., 2020 ; Aldea, 2022 ; Khlat et al., 2022 ), but to the best of our knowledge, none have addressed the differences in the lived experiences of wellbeing among older migrant and native populations with a focus on coping strategies. Furthermore, there is a paucity of literature comparing the experiences of wellbeing and coping strategies between countries that implemented contrasting COVID-19 containment measures.

We aim to bridge this gap by comparing the experiences of older adults in Italy and Switzerland – countries that implemented different COVID-19 containment measures – nearly 2 years after the pandemic onset. Specifically, we study older Swiss natives residing in Switzerland, older Italian natives residing in Italy, and older Italian migrants residing in Switzerland. This allows us to explore the experiences of wellbeing of older adults who lived under strict restriction measures, namely Italian residents, to those of adults who lived under more relaxed measures, namely Swiss natives and Italian migrants living in Switzerland. Furthermore, comparing Swiss natives and Italian migrants allows us to analyze the experiences of two groups who lived the pandemic in the same context, yet who have had different life courses. More particularly, because older Italian migrants in Switzerland often have attachments to Italy and take part in transnational practices ( Ludwig-Dehm et al., 2023 ), their inclusion in the study allows us to explore how the situation in their country of origin impacted their COVID-19 experiences from abroad.

This paper aims to analyze (1) How the COVID-19 pandemic impacted the experiences of wellbeing of older adults in Switzerland and Italy and (2) How older adults coped with the stressors brought about by the pandemic, in particular social distancing.

2 Contextual background: the Swiss and Italian contexts

Despite the geographical proximity between Switzerland and Italy, the two countries implemented quite different containment measures as a response to the virus.

Compared to other European countries, on average Switzerland implemented less stringent containment measures throughout the pandemic, despite being just as impacted ( Pleninger et al., 2022 ). The first phase of the pandemic, classified by the Federal Council as an “extraordinary situation,” lasted from March 16 to June 19, 2020 ( Sager and Mavrot, 2020 ; Maggiori et al., 2022 ; Pleninger et al., 2022 ). From March 16 until April 26, the Swiss government gradually imposed measures closing borders, canceling cultural and sports events, banning all public and private manifestations, closing schools, restaurants, bars, as well as shops and services deemed to be unessential, and banning gatherings of more than five people. Older adults in particular were advised to stay at home and to avoid in-person social interactions with members outside their household. From April 26, 2020 containment measures were slowly eased, and on June 19, 2020, the classification of the pandemic changed from “extraordinary” to “special” ( Sager and Mavrot, 2020 ; Pleninger et al., 2022 ).

During the next 2 years, Switzerland saw a series of tightening and easing of containment measures, which included regulations on mandatory vaccines or COVID-19 tests to access bars and restaurants, and mandatory masks to be worn in shops and public transport. All restrictions were then lifted on April 1, 2022 ( FOPH, 2022 ).

Throughout the pandemic up until the data collection for this article – between December 2021 and March 2022 – the Swiss government largely relied on cooperation from the public. Although in certain periods shops, restaurants, and schools were closed, Swiss residents still enjoyed a certain amount of freedom to move and have social gatherings, albeit limited. Overall, it was left up to the individuals to regulate their behaviors within certain limits.

The Italian government, on the other hand, imposed more stringent measures throughout the pandemic. Late January 2020, the government declared a national emergency, and in February 2020, Italy was the epicenter of the health crisis in Europe ( Ferrante, 2022 ). The Italian government quickly established lockdown “red” zones in certain areas of Northern Italy, which led to the closure of schools and restrictions of movement: residents could leave their areas of residence only for necessities like work, health reasons or family emergencies, or grocery shopping. These restrictions were applied in waves to the entire country, and on March 11 the government imposed a national lockdown, also named the “stay at home” decree ( Bull, 2021 ). This entailed closure of borders, schools, restaurants and bars, and all nonessential shops and services. Travel between regions was prohibited and residents' movement was only allowed for essential reasons. The first Italian lockdown ended on May 3, 2020, after which most shops, restaurants, bars, and services gradually reopened while maintaining COVID-19 safety protocols ( Bosa et al., 2021 ).

During the next 2 years, Italy also experienced a series of loosening and tightening of restrictions, but these were often more stringent than the ones imposed in Switzerland. For instance, during the second wave of the pandemic, which took place in autumn of 2020 and winter of 2021, curfews from 11 pm to 5 am were mandated and restaurants and bars had to close at 6 pm. During this time, Italian residents were strongly recommended to leave their homes only for work or health reasons, and these restrictions were gradually eased by mid-2021 ( SkyTG24, 2020 ; Bosa et al., 2021 ). In April 2022, Italy declared an end to the state of emergency, and thereafter lifted all restrictions ( Amanto, 2022 ).

Both Italy and Switzerland were successful in containing the spread of the virus ( Ferrante, 2022 ; Pleninger et al., 2022 ), but at what cost to people's wellbeing?

3 A theoretical framework to understand wellbeing and coping strategies among older adults

3.1 wellbeing.

Research on wellbeing largely encompasses two forms: objective wellbeing and subjective wellbeing. The first refers to objective indicators like income, health, and living conditions. The second refers to individuals' experiences of wellbeing and to their evaluations of their lives. It is often measured with indicators like positive and negative affect, happiness, life satisfaction, and satisfaction with various life domains like social relationships, financial situation, and neighborhood conditions ( Bartram, 2012 ; Diener, 2012 ; Veenhoven, 2012 , 2017 ). In this paper, we use the term wellbeing to refer to the latter concept – to individuals' subjective experiences of wellbeing.

Some objective indicators are indeed correlated to subjective indicators – being in good health, for instance is positively associated with life satisfaction ( Helliwell, 2003 ; Deaton, 2008 ; Clark et al., 2018 ) and, to a certain extent, so is income ( Clark et al., 2008 ; Clark, 2011 ; De Jong, 2015 ). Studies have also debated to what extent wellbeing is dependent on genes and individual personality traits ( Bartels, 2015 ; Røysamb et al., 2018 ), and to what extent it is dependent on external factors like social contexts and life events ( Helliwell and Putnam, 2004 ). But overall, the consensus is that wellbeing is influenced by both genetic and environmental characteristics ( Røysamb et al., 2014 ; Luhmann et al., 2021 ).

Most studies employ a quantitative approach and explore a wide array of determinants of wellbeing, ranging from age, to health, to income and education, to relationships and divorce, to social norms and institutions, and so on ( Clark et al., 2018 ). Qualitative studies on wellbeing are less common ( Bartram, 2012 ), but they valuably provide information on participants' perceptions, views and beliefs that are unaffected by researchers' pre-determined ideologies ( Delle Fave et al., 2011 ). Especially in a context like that of the COVID-19 pandemic – a disruptive process that homogeneously categorized an entire group as vulnerable and forced individuals world-wide to reorganize their lives – a qualitative approach allows for nuanced, in-depth analyses of people's experiences of wellbeing (and vulnerability).

3.2 Older adults' vulnerability

Independently of the pandemic context, older adults are often characterized as particularly frail and vulnerable ( Fried et al., 2001 ; Clegg et al., 2013 ). This is often due the age-related decline in physiological and psychological systems, which renders this population vulnerable to falls, hospitalization, or sudden health changes triggered by minor events, and makes them more reliant on others for care ( Fried et al., 2001 ; Clegg et al., 2013 ). But vulnerability in old age is not a dichotomous state of vulnerable vs. not vulnerable, as was suggested in the public discourse during the COVID-19 pandemic. According to the life-course approach employed by Spini et al. (2017) , vulnerability is defined as:

“a weakening process and a lack of resources in one or more life domains that, in specific contexts, exposes individuals or groups to (1) negative consequences related to sources of stress, (2) an inability to cope effectively with stressors, and (3) an inability to recover from stressors or to take advantage of opportunities by a given deadline.” ( Spini et al., 2017 , p. 8)

It is a dynamic process between stress and resources that occurs at the intersection of different areas of life (like health, work, family, etc.), and on several levels (macro-, meso-, or micro-levels) throughout the life course ( Spini et al., 2017 ). When faced with a stressful situation like the COVID-19 pandemic, individuals must rely on the resources they accumulated throughout the life course – referred to as reserves ( Cullati et al., 2018 ) – in order to cope with life adversities. These reserves include, but are not limited to, physical and mental health, economic savings, cultural capital resulting from education, social networks, and emotional and cognitive reserves ( Cullati et al., 2018 ). It is in times of shocks that these reserves become the most important and mediate the impact of stressors on individuals' wellbeing; it is also during these adverse periods that inequalities between individuals' reserves become the most apparent ( Widmer, 2022 ), leading to situations of vulnerability.

In old age, physical reserves diminish, and older adults' ability to fight infectious diseases decreases, putting them in a vulnerable situation ( Bajaj et al., 2021 ). However, physical reserves are related to events and conditions throughout the lifespan. For example, the combination of disadvantageous childhood socioeconomic conditions, coupled with adverse adult socioeconomic conditions, increase the probability of chronic health diseases ( Galobardes et al., 2007 ). Aging adults are thus not all equally vulnerable to the risks associated with COVID-19; their vulnerability is associated to a wide variety of life-course experiences and factors, only some of which directly related to age ( Oris et al., 2020 ; Sneed and Krendl, 2022 ).

3.3 Pandemic impact on older adults' wellbeing

In the context of the COVID-19 pandemic, researchers have studied different measures related to wellbeing, like loneliness, social isolation, worry, anxiety, and others. This section draws on the literature focusing on various experiences of wellbeing during the pandemic among older adults.

Following the implementation of virus containment and social distancing measures, many countries reported an increase in loneliness among older adults in comparison to pre-pandemic levels ( Luchetti et al., 2020 ; Seifert and Hassler, 2020 ; Holaday et al., 2021 ; Macdonald and Hülür, 2021 ; Rodney et al., 2021 ; Van Tilburg et al., 2021 ; Zaninotto et al., 2022 ; see also literature review by Su et al., 2023 ). Feelings of loneliness were particularly prevalent among older adults with no children, lower-income individuals, those living alone, and those reporting depressive symptoms ( Seifert and Hassler, 2020 ; O'Shea et al., 2021 ), which highlights the role of resources and reserves in mediating the pandemic's impact on wellbeing.

Furthermore, older adults in countries all around the world experienced higher levels of stress, worry, anxiety, and depression in comparison to pre-pandemic levels. These negative mental health outcomes were more common among older single adults, among older adults of lower socioeconomic groups ( Kola et al., 2021 ; Webb and Chen, 2022 ; Wettstein et al., 2022a ; Zaninotto et al., 2022 ), among those with poor self-rated health ( Wettstein et al., 2022a ), and among those who were already socially isolated prior to the pandemic ( Macleod et al., 2021 ). Social isolation is correlated to declining physical and mental health, increased mortality, and lower quality of life, and the social distancing measures introduced by the pandemic exacerbated these risks ( Macleod et al., 2021 ).

Most studies published to date, in May 2023, concentrate on the initial weeks of the pandemic and largely focus on singular countries. Atzendorf and Gruber (2022) 's research, however, focused on the weeks following the first wave, between June and August 2020 and used SHARE data to analyze the medium-term consequences of the first pandemic wave across 25 European countries and Israel. They found that older adults in countries with high death rates and stringent measures were at increased risk of feeling depressed or lonely. Similarly, Mendez-Lopez et al. (2022) used the same data and revealed that countries' greater stringency in physical distancing measures was associated with worse mental health. This is particularly pertinent for this paper, as both Italy and Switzerland were badly hit by the pandemic ( Ferrante, 2022 ; Pleninger et al., 2022 ), but they differed in containment strategies: while Italian residents were severely limited in their mobility, Swiss residents benefitted from a certain amount of freedom. Atzendorf and Gruber (2022) revealed that Italian older adults reported increased feelings of loneliness and depression after the pandemic onset to a greater extent than Swiss older adults.

The only study to date analyzing older adults' wellbeing during the two years following the pandemic onset showed that most older Europeans did not feel lonely before or during the pandemic. However, for some, feelings of loneliness increased, particularly among the less educated, those living alone, and those isolated at home ( König and Isengard, 2023 ).

Moreover, the characterization of older adults as a homogeneous, exceptionally vulnerable population ( Petretto and Pili, 2020 ; Seifert, 2021 ) engendered negative self-perceptions of aging ( Losada-Baltar et al., 2021 ; Seifert, 2021 ), which have been associated with loneliness and psychological distress among older adults ( Losada-Baltar et al., 2021 ). Their homogenous representation and the resulting ageist narrative also led to feelings of anger, increased anxiety, and perceptions of loss of autonomy and individualism by this older population ( Derrer-Merk et al., 2022a , b ).

Although research has documented the negative impact of the pandemic on older adults, studies have also suggested that in some ways, older adults did not suffer as much as their younger counterparts, as documented in the literature review by Seckman (2023) . Older adults in the United States reported less pandemic-related stress, less social isolation ( Birditt et al., 2021 ), and greater emotional wellbeing ( Carstensen et al., 2020 ) than younger adults. The same result was found among Chinese adults ( Jiang, 2020 ). Similarly, in Italy older adults reported less loneliness compared to younger age groups ( Luchetti et al., 2020 ).

Independently of the pandemic context, older migrants are more vulnerable to loneliness and social isolation due to language and cultural barriers, low social capital, and dependence on children for support ( Neville et al., 2018 ; Sidani et al., 2022 ). Moreover, older migrants often occupy disadvantaged socioeconomic positions and are in worse health than natives in the host country ( Bolzman and Vagni, 2018 ; WHO, 2018 ). The pandemic and the related reduced social contacts may have thus rendered older migrants particularly vulnerable to social isolation, loneliness and negative mental health outcomes ( Pan et al., 2021 ; Sidani et al., 2022 ). In fact, a study on older Chinese migrants in Belgium and the Netherlands revealed that reduced social participation and financial insecurity increased migrants' loneliness levels ( Pan et al., 2021 ).

Furthermore, migrants often engage in transnational practices, linking them in various ways to their country of origin ( Ciobanu and Ludwig-Dehm, 2020 ). The pandemic restrictions changed some of these transnational practices through travel bans and border closures ( Nehring and Hu, 2022 ), which may influence older migrants' wellbeing. A survey conducted within the same research project as this paper, found that Italian migrants in Switzerland reported higher levels of worry about the COVID-19 pandemic than Swiss natives, and this difference is largely explained by engagement in transnational practices ( Ludwig-Dehm et al., 2023 ).

Despite the increasing proportion of older migrants in Europe ( UNDESA, 2020 ), research on the impact of the pandemic on older migrants' wellbeing is scarce.

3.4 Coping strategies of older adults

Research has shown that aging adults are capable of adapting and coping to various events and circumstances ( Klausen, 2020 ; Settersten et al., 2020 ). Coping refers to the cognitive and behavioral efforts one carries out to prevent, tolerate, or diminish certain situations ( Lazarus and Folkman, 1984 ; Carver, 2013 ; Biggs et al., 2017 ), and studies have found that older adults are particularly able to engage in such behaviors to diminish stressors ( Yancura and Aldwin, 2008 ; Carstensen et al., 2020 ). Coping strategies are often grouped into emotion-focused and problem-focused strategies ( Lazarus and Folkman, 1984 ; Aldwin and Revenson, 1987 ; Biggs et al., 2017 ). The first refers to strategies intended to regulate one's emotional reactions to the problem, while the latter refers to behaviors and cognitions aimed at directly managing or solving a problem ( Yancura and Aldwin, 2008 ; Biggs et al., 2017 ). This includes strategies aimed at avoiding thinking about the problem – like keeping oneself busy – as well as strategies aimed at finding the positive aspects of a stressful situation ( Aldwin and Yancura, 2004 ).

Older adults' ability to engage in these strategies can be partly explained by Carstensen's (2021) Socioemotional Selectivity Theory, which posits that social and emotional goals change depending on the perception of how much time one has left to live. As one grows older or approaches the end of their life due to illnesses or frailty, goals shift and people tend to value smaller and more meaningful social networks, they tend to spend more time with close partners, and they use cognitive resources to process more positive information ( Carstensen, 2021 ).

Another aspect related to older adults' coping abilities concerns the aforementioned reserves accumulated throughout the life-course. Accumulation of social resources, cultural and economic capital, health reserves, and the acquisition of coping skills allow older adults to endure stressful situations or, on the contrary, the lack of such reserves can penalize them ( Grundy, 2006 ; Cullati et al., 2018 ; Settersten et al., 2020 ).

In addition to the wellbeing consequences for older adults, studies have addressed the coping mechanisms developed by this population throughout the first wave of the pandemic. In a qualitative study, Gonçalves et al. (2022) interviewed older adults in Brazil, the United States, Italy, and Portugal, and revealed that social isolation engendered feelings of restriction in terms of interaction with friends and family and ability to participate in leisure activities. At the same time, older adults were also able to cope with the situation by dedicating their time to hobbies, using technological resources to stay close to friends and family, or involving themselves in religious and spiritual activities. Despite the different cultures and contexts of this study's participants, researchers found homogeneity in their coping mechanisms. Several studies confirmed these findings with different samples of older U.S. American adults ( Finlay et al., 2021 ; Fuller and Huseth-Zosel, 2021 ; Whitehead and Torossian, 2021 ), and Bustamante et al. (2022) revealed that time spent in parks and outdoor spaces boosted physical, mental, and social wellbeing.

Similarly, Mau et al. (2022) found that for older Danish adults, adapting to the situation by reframing their mindset, finding ways to maintain social contacts and a sense of community, and staying active were important coping behaviors that helped them maintain a good level of wellbeing. In Italy, older adults experienced the first pandemic wave in heterogeneous ways: those who felt alone pre-pandemic expressed that isolation had a negative impact on their wellbeing. Others were able to cope with the situation by exploring hobbies and maintaining contacts with friends and family through telephone use ( Cipolletta and Gris, 2021 ).

However, the only study on older migrants' wellbeing and coping strategies by Pan et al. (2021) found that neither problem-focused coping strategies, nor emotion-focused coping protected against increased loneliness during the pandemic.

These studies reveal that, at least for the first half of 2020, older adults employed coping mechanisms to endure the pandemic, but we still know little of their experiences after the first COVID-19 wave. A longitudinal qualitative study on Canadian older persons explored their experiences over a 10-month period from May 2020 to February 2021 ( Brooks et al., 2022 ). It found that the longevity of pandemic restrictions was partially responsible for older adults' declines in wellbeing. Simultaneously, participants used similar coping mechanism employed during the first pandemic wave to maintain their wellbeing: they stayed active, found ways to stay in contact with friends and family, and adopted positive mindsets.

Nonetheless, cross-country research on the experiences of wellbeing among older adults, and more particularly in the years following the pandemic onset, is still scarce. We therefore aim to bridge this gap by exploring the lived experiences and coping mechanisms of older individuals in two countries that had contrasting COVID-19 containment measures like Italy and Switzerland. Furthermore, we analyze how having connections to both countries, as is the case of Italian migrants in Switzerland, influences the lived experiences of these individuals.

4 Data and methods

Our study focuses on three groups of older adults (65+): (1) Swiss natives, defined as individuals who were born in Switzerland and whose parents were also born in Switzerland, (2) Italian international migrants from the south of Italy, defined as individuals who were born in southern Italy, whose parents were also born in Italy, and who migrated to Switzerland, and (3) Italian natives, defined as those who were born in the south of Italy, resided in the south of Italy at the time of the research, and whose parents were also born in Italy. There are several reasons for the inclusion of these specific groups in our study. First, Italians constitute one of the largest cohorts of foreign nationals aged 65 and above residing in Switzerland ( FSO, 2020 ). Second, a significant part of older Italians migrated to Switzerland between the 1950s and 1970s, with the majority originating from economically disadvantaged regions of Southern Italy ( Wessendorf, 2007 ). They primarily migrated for financial reasons or to reunite with family who had relocated as labor migrants ( Bolzman et al., 2004 ; Riaño and Wastl-Walter, 2006 ), and we therefore analyze older adults with a very specific migration background. Third, by comparing migrants from Southern Italy to natives from the same regions, we can explore the lived experiences of individuals who were raised in similar social contexts.

The sample for this paper is derived from an original quantitative survey conducted between June and November 2020 in the project TransAge: “Transnational aging among older migrants and natives: A strategy to overcome vulnerability.” Respondents to the qualitative interviews had already participated to the TransAge survey and had agreed to be further contacted for a follow-up interview. In total, 31 individuals participated to the study, of which 11 were Swiss natives, 10 were Italian migrants residing in Switzerland, and 10 were Italian natives residing in Italy.

To ensure diversity of wellbeing experiences among each of the three groups, we attempted to recruit individuals with low and high levels of life satisfaction. To do so, we based ourselves on Diener's Satisfaction with Life Scale ( Diener et al., 1985 ), included in the TransAge questionnaire. More specifically, we focused on the scale item “I am satisfied with my life.” In the survey, participants were asked to indicate the strength of their agreement with this statement on a scale ranging from 1 (strongly agree) to 7 (strongly disagree). We thus contacted a roughly equal number of participants who stated being satisfied with their lives (scores 6 or 7) and participants who were less satisfied (scores 5 or less). Simultaneously, we checked the general life satisfaction scores drawing on the 5-item scale to assure coherence between the single-item and the total score ( Diener et al., 1985 ).

The first author conducted semi-structured one-to-one interviews with the 31 community-dwelling older adults between December 2021 and March 2022, during the fifth wave of COVID-19, when social distancing was still strongly advised. Consequently, all interviews were done by telephone, 1 except for one participant who preferred to meet in person. Participation in the study was voluntary, and all participants gave oral consent to be interviewed and recorded. Interviews lasted an average of 45 min, and they were conducted in French or Italian. They were audio-recorded and subsequently transcribed verbatim and anonymized. Participant quotes in this paper were translated into English by the first author, and every participant was given a pseudonym.

Participants were asked open-ended questions that prompted them to reflect on their experiences throughout the pandemic. First, they were asked to describe their feelings at the beginning of the pandemic, any impact that the confinement period had on their wellbeing, on their social habits, oron their daily lives. They were also encouraged to share how they coped with this period. They were then asked to reflect on the years after the onset of the sanitary crisis and describe any difficulties they faced and any strategies used to surmount these difficulties. Participants were also invited to share what their daily and social lives looked like at the time of interview, and how they felt about any long-lasting changes they may have experienced.

Interviews were analyzed using an inductive thematic analysis using qualitative coding software NVivo. The study was approved by the Ethics Committee of the Faculty of Social Sciences of the University of Geneva.

5.1 Sample description

The 11 Swiss natives and 10 Italian migrants resided in the Swiss cantons of Geneva, Vaud, or Ticino, while the 10 Italian natives resided in the Italian regions of Sicily, Apulia, Sardinia, Abruzzo, Basilicata, or Campania. Participant characteristics by group are shown in Table 1 . In comparison to the larger TransAge quantitative study, there is an over-representation of participants with medium and higher level of education among Italian migrants and natives, which will be taken into consideration in the discussion of the results.

Table 1 . Sample charactertistics.

5.2 Comparative accounts of wellbeing in times of pandemic

When recounting their experiences throughout the first 2 years of the pandemic in Switzerland and Italy, participants across the three groups coupled their narratives, whether positive or negative, with coping strategies they employed to manage the impact of the pandemic on their wellbeing. The themes that we identified correspond to emotion-focused coping and problem-focused coping strategies documented in the coping literature ( Lazarus and Folkman, 1984 ; Aldwin and Revenson, 1987 ; Biggs et al., 2017 ). Emotion-focused coping refers to strategies aimed at regulating the emotions that arise because of a stressful situation, which also includes engagement in activities as a way to distract oneself. Problem-focused coping, on the other hand, refers to behaviors and cognitions targeted toward solving or managing a problem ( Yancura and Aldwin, 2008 ). Strategies like social contact through telephone use involves elements of both emotion-focused and problem-focused coping. It refers to emotional support received by friends and family, it can entail concrete help in understanding how to confront an adverse situation, and it is a strategy directed at compensating for decreased in-person contact ( Aldwin and Yancura, 2004 ).

Table 2 shows the behaviors adopted by participants that correspond to these two overarching coping mechanisms. We found that certain strategies adopted during the first lockdown were no longer used at the time of interview. Thus, in Table 2 , we list the themes found in the data by pandemic period.

Table 2 . Coping strategies used at pandemic onset and at time of interview.

During the first months of the pandemic, the primary emotion-focused strategies adopted by older adults in our sample related to acceptance of the health crisis, keeping busy through hobbies and exercise, appreciation of the natural environment, and attitudes aimed at “finding the silver lining,” which involves strategies aimed at trying to find the positive aspects of the problem at hand, and which the literature often refers to as cognitive reframing ( Aldwin and Yancura, 2004 ; Robson and Troutman-Jordan, 2014 ). In terms of problem-focused coping, participants evoked the importance of social distancing measures both during the initial lockdown and at the time of interview, and many later relied on vaccines as a mean to decrease the probability of severe illness.

The subsequent sections are organized as follows: First, we detail, by group, participants' experiences of wellbeing during the first lockdown and the coping strategies they adopted to face this period. Then, we analyze how social distancing measures and decreased social contacts impacted participants in each of the three groups, and we outline participants' social habits and coping strategies at the time of interview.

5.2.1 Wellbeing during the first lockdown

Although participants in all three groups used similar coping strategies throughout the pandemic, their narratives of wellbeing differed.

5.2.1.1 Experiences of Swiss natives

All Swiss native older adults, except for one, described the first confinement period in positive terms and expressed not having been particularly bothered by it. They often associated their wellbeing to being able to keep busy through various hobbies and interests, and by enjoying the natural landscapes around them, as indicated in the following excerpts:

“I think I was very relaxed…I have so many books at home...I have the watercolors, I have so many things to do here, creatively, with my hands or with my head, it doesn't bother me, so...the confinement didn't bother me at all.” (Irène, 77, F, Swiss native)     “So, at home, my wife plays the piano. She has a gentleman who comes to the house. Oh yeah, she hasn't had a lesson in a year at home, but she took lessons with Zoom. You know how it is. So, she has a lot of work, piano homework. I did a little bit of crafting. I did a little bit of Spanish with French-Spanish classes.” (Nicolas, 71, M, Swiss native)     “We remained a little locked up. But we had…it was a beautiful weather. There was the spring and everything, everything was beautiful. We enjoyed our patio. We got back to reading. We did a lot of stuff like that.” (Lydia, 79, F, Swiss native)

Some Swiss participants mentioned increased telephone use to share moments with friends and family. Others described their wellbeing by comparing themselves to others, thus engaging in cognitive strategies to frame their attitude and outlook on the situation. François, for instance, often spends part of the year in Barcelona, and when talking about his wellbeing, he compares the Swiss restrictions to those of Barcelona. He elaborates:

“We were very lucky because we weren't confined like…in Barcelona. In Switzerland, that wasn't the case. Of course, there were things we couldn't do any more, but there was still a lot for us to do. We could take the car, we could go for a walk. Well, the borders were closed. Well, we didn't suffer, my wife and I…our sons either.” (François, 81, M, Swiss native)

When reflecting on the virus-containment measures, others simply stated that they just had to accept the situation and adapt their behaviors accordingly. Pierre, for example, states:

“You have to adapt. We adapt by respecting the rules, not like people who cheat [by not following the rules]. We respect the rules, but we adapt.” (Pierre, 71, M, Swiss native)

Overall, the first months of the pandemic were described in positive terms by most of Swiss older adults. Most of them portrayed themselves as being in good health and they did not evoke fears related to the virus. However, one Swiss participant expressed the negative impact of this period on his wellbeing. He recounts:

“[We lived this period] quite badly because we were old, very old. The Ticino police chief was more or less telling everybody to put us in the freezer. I mean, not quite like that…he made a statement that caused quite a stir…[The situation] was not very conducive to being cheerful, let's say.” (Gianni, 88, M, Swiss Native)

For Gianni, the government lockdown meant being “stuck at home,” as he says, and relying on institutional support. His quote shows the way he experienced the confinement measures and the public discourse as an older-old person.

5.2.1.2 Experiences of Italian migrants in Switzerland

Similarly to Swiss natives, Italian migrants residing in Switzerland used cognitive strategies to frame the lockdown's impact on their wellbeing. They, too, evoked Switzerland's lenient containment measures as an important aspect that helped them surmount this period, particularly in terms of the freedom it gave them to spend time in nature. Giulia, for example, explains:

“Here in Switzerland, here in Geneva, I didn't feel this need for freedom like in other countries. For me, we were free here. I live near a park, I could take my walk every day. I have a small but very nice little apartment that has visibility on both sides, left and right, so I didn't feel like I was in prison.” (Giulia, 70, F, Italian migrant)

Italian migrants also turned to activities like reading, taking walks, and exercising to keep themselves busy during this period. However, although they lived the pandemic in the same context as the Swiss natives, there was more heterogeneity in Italian migrants' narratives of this containment period. While most stated that they simply accepted the situation and the lockdown did not negatively impact their wellbeing, some expressed feelings of loneliness and isolation. Gabriele (69, M), for example, says he felt isolated from the outside world at the beginning of the pandemic, he described his life during this period as monotonous. However, he kept himself busy by going on walks and exercising.

Others tried to overcome their feelings of loneliness by staying in communication with family, but it was not always helpful. When asked about any difficulties he faced during the lockdown, Alberto explains:

“A little bit of loneliness and missing family, that's it. It weighed on me a little bit. We used to phone my children, but no luck. My children also suffered; my youngest daughter suffered a lot and now we slowly recover.” (Alberto, 77, M, Italian migrant)

Italian migrants in Switzerland still hold transnational ties to their country of origin; a quantitative analysis of the TransAge survey found a higher level of worry about the pandemic among Italian migrants in Switzerland in comparison to Swiss natives ( Ludwig-Dehm et al., 2023 ). We were therefore interested in investigating whether Italian migrants evoked the COVID-19 situation in Italy when describing their own experiences of wellbeing, but none of our participants organically elicited Italy's situation in their narratives. We subsequently asked participants whether they were impacted in any way by the pandemic in Italy, and responses were heterogeneous. A large part expressed not having been impacted at all, others stated that they were sorry for the high numbers of deaths in Italy and they kept in contact with family, but were not particularly affected. Few of our participants, however, disclosed the emotional suffering they experienced due to Italy's high death rates, as demonstrated by the following quotes:

“I felt tremendous suffering […] I followed a lot, every day I was watching the Italian news. And it was, for me it was just – I don't want to say worse than the war, it was a virtual war, people dying without weapons, people dying without the bombs, without being machine-gunned, but they were dying like flies.” (Giulia, 70, F, Italian migrant)     “Terrible, I felt really bad, I mean I don't know why we got to that point.” (Sara, 78, F, Italian migrant)

Although Italian migrants and Swiss natives lived the pandemic in the same context and both used similar coping strategies during the first confinement period, interviews show that Italian migrants' experiences were slightly more heterogeneous than Swiss natives', with a few migrants expressing feelings of loneliness and emotional anguish, emotions that were absent in Swiss natives' accounts.

5.2.1.3 Experiences of Italian natives

In comparison to Swiss natives and Italian migrants in Switzerland, most Italian natives residing in Italy expressed feelings of worry, sadness, and fear when recounting their lockdown experiences, but most of them coupled their hardships with feelings of acceptance. Tommaso, for example, recounts:

“To hear on television, from the media, that there are deaths and deaths and deaths, obviously the concern is there. The fear, the terror even, of suffering these negative effects.” (Tommaso 84, M, Italian native)

But later, when discussing the lockdown, he continues:

“I stayed peacefully at home with a nice long beard, growing it out. I accepted it, though, because those were the rules. You had to accept them.” (Tommaso, 84, M, Italian native)

Similarly, Paolino couples the dismay brought on by the pandemic lockdown with feelings of acceptance, as well as behaviors aimed at avoiding contagion. He explains:

“The beginning of the pandemic I accepted it begrudgingly, at home, and I stayed at home despite my habits, because having lived a life always on the move – until now I was always around. That thing, the pandemic, I accepted it, and for 3 months I stayed at home, I would only go get some groceries, the bare minimum.” (Paolino, 86, M, Italian native)

In contrast to Swiss natives and Italian migrants, few Italian natives mentioned having turned to hobbies to fill up their time during the first lockdown. Some mentioned the importance of spending time outside, of having a balcony or a garden. Most of them cited phoning friends and family for emotional support, to pass time, and to update each other on their health, and most declared having used the phone for communication more than pre-COVID times. To respect social distancing rules, one participant even used intercom to communicate with family in the same building; she says:

“We used to talk to each other by intercom and by phone, we all live in the same building, so by intercom, by phone we used to talk to each other, and then if somebody went out, they would walk by the kitchen door, which was made of glass, and then we would see each other.” (Rosa, 71, F, Italian native)

Despite the coping strategies employed by Italian natives, their narratives of the lockdown presented an overarching theme of dejection, which was less present in Italian migrants' experiences and nearly absent in those of the Swiss natives in our sample.

5.2.2 Wellbeing after 2 years of the COVID-19 pandemic: the role of social contacts

Notwithstanding the different narratives of wellbeing among the three groups, the previous sections indicate that everyone inevitably experienced a decrease in physical social contacts resulting from the COVID-19 containment policies. Given the importance of social networks for individuals' wellbeing ( Helliwell and Putnam, 2004 ; Elgar et al., 2011 ; Amati et al., 2018 ), we aimed to inquire how social distancing regulations impacted participants' perceived wellbeing in the 2 years after the onset of the pandemic.

Our interviews reveal heterogeneous responses to social distancing; nonetheless, regardless of the perceived impact on their wellbeing, most participants employed behavior-focused coping strategies aimed at reducing probability of contagion and illness. These strategies consisted of either vaccination for the participant, social distancing habits, or a combination of the two. In some cases, these strategies were successful in supporting participants' experienced wellbeing. In other cases, they preserved one's physical wellbeing at the cost of their subjective wellbeing.

In the next sections, we explore how each of the three groups was impacted by decreased social contacts, how these sentiments developed throughout the pandemic, and how participants employed the above-mentioned coping strategies at the time of interview.

5.2.2.1 Experiences of Swiss natives

Just like the lockdown did not seem to negatively impact most Swiss older adults in our study, neither did the imposed social distancing measures and related decrease in social contacts. Most of them experienced a slight change of social habits, which entailed seeing friends and family less frequently during the previous 2 years in comparison to pre-COVID times. However, these changes did not have a consequential negative impact for most of our Swiss participants. Social distancing was often described as bothersome or strange, but easily managed. Martin, for example, states:

“Yeah, [the pandemic] restricts our freedom to see – as I'm a pretty tactile person, it's true that it changes me a little bit. Friends, I kiss them less. That's what affects me a little bit more – I have to be less, much less tactile than I was with everyone, to give kisses to the left and to the right. Well, it's a bit weird.” (Martin, 75, Swiss Native)

This quote represents the sentiments expressed by most Swiss natives: they were not completely unaffected, but they were able to adapt to the changes in social habits without important repercussions for their wellbeing. At the time of interview, nearly 2 years after the pandemic onset, most Swiss older adults explained their social habits were similar to their pre-pandemic habits, but they also adopted strategies to be able to fulfill their social desires while avoiding contagion or severe illness. Most Swiss participants mentioned being vaccinated and expressed the importance of listening to scientists' advice on the preventative measures to take. These strategies helped them adjust their behaviors accordingly and feel more protected. Martin, for instance, has resumed seeing friends, but only under certain self-imposed rules. He explains,

“If we see each other, we are all vaccinated. We are not safe from catching it but at least we are less likely to get sick. And then, we avoid those who don't want to be vaccinated or those who are not vaccinated.” (Martin, 75, Swiss native)

However, one Swiss participant shared the negative experiences that followed him and his wife throughout the course of the pandemic. During the lockdown, Gianni expressed being “stuck at home,” and this lack of freedom and decreased social contacts persisted until the time of the interview, 2 years later. He says,

“Now with these problems of…the danger of contagion, and so it makes us less, less mobile, less free to live, right? Basically now, even though the lockdown has not been declared, we try to go out as little as possible, not to mingle with people so we don't get infected.” (Gianni, M, 88, Swiss native)

While most Swiss older adults were able to resume their social lives by adopting behaviors to avoid illness, the social distancing measured employed by Gianni – the oldest among our Swiss participants – allow him to preserve his physical wellbeing at the cost of his subjective wellbeing.

5.2.2.2 Experiences of Italian migrants in Switzerland

In comparison to older Swiss natives, the perceived impact of social distancing measures was more heterogeneous among Italian migrants. At the time of interview, only a minority of participants said they had resumed their pre-pandemic social habits, although most slowly started seeing small groups of friends again. Like in Gianni's case, for many Italian migrants, the social distancing strategies adopted to preserve their physical wellbeing had negative repercussions on their experienced wellbeing. One participant, for example, shared that the fear of contagion remained even after containment restrictions were eased, and his personal relationships suffered. He explains,

“I lost touch with friends, you couldn't get together, you couldn't go shopping, the only thing I could do was go [walk] in the forest. Then, even when the restrictions were eased, it had affected me so much that it was hard to get together. When we got together […] we had a drink and then left. There was always that fear between us.” (Giacomo, 68, M, Italian migrant)

Giacomo looks back at his life before the pandemic with melancholy, but he also elicits the importance of acceptance and reframing one's mindset to surmount the situation. He shares:

“[Before COVID-19] we used to get together on Friday nights, play cards, drink, smoke, and for 2 years we haven't done it and I don't think we're going to start again. It's difficult because people have become distrustful, we've been wounded and we're licking our wounds. Let's put it this way. You have to get over it, direct your life differently and move on. I don't want to stay at home waiting for death.” (Giacomo, 68, M).

Although some participants were wary of resuming social activities at the time of interview, most slowly started seeing friends again while continuing to employ social distancing measures. Giulia, for instance, explains:

“[Before the pandemic] maybe we went to the restaurant once a month, or once every 2 months. But that was a lot. But we haven't done this anymore, and I didn't – and we don't even feel like doing it anymore. Now if we go to a restaurant, we go at noon…and we stand outside on the terrace because we keep being careful.” (Giulia, 70, F, Italian migrant)

Despite the slow return to a social life and the continued safety measures employed, the pandemic had a long-lasting impact on the wellbeing of most Italian older migrants, as evidenced by the following excerpts:

“I feel insecure, maybe because of the pandemic, because of the war that's going on 2 […] I feel insecure and I tell myself I don't need this […] Insecure in the sense that I say, enough of the pandemic; insecure not physically, but in the sense that it destabilizes me [mentally] […] In the sense that I used to be able to imagine the following years and now I can't.” (Sara, 78, F, Italian migrant)     “It's 2 years that I lost and that I cannot get back. […] I lost 2 years that I won't get back. I don't even know if I'll be able to – to feel better.” (Giulia, 70, F, Italian migrant).

5.2.2.3 Experiences of Italian natives in Italy

The perceived impact of the social distancing measures was notably detrimental for the experienced wellbeing of Italian natives in Italy. Most cited the lack of social contacts as the primary difficulty faced throughout the pandemic. For many, the fear instilled by the pandemic prevented them from resuming their social activities at the time of interview, despite most participants being vaccinated. This engendered feelings of sadness, anxiety, and loneliness among many Italian participants, as evidence by the following quotes:

“What I dislike is not being able to have company, because I'm all about friendships, company, laughter, and I don't like loneliness. […Before the pandemic] we used to organize trips with an association, so we would spend 15 days together, and every 2 months we would meet in an institution and spend the day together, we would eat together. With girlfriends, we would go out and take a walk in the countryside when we had nice days, and so I miss all of that now.” (Martina, 84, F, Italian native)     “Now the fact of going out and putting the mask on […], continually having to disinfect your hands when you go out, when you go get groceries, having to be careful not to get too close to people, [hoping] that in stores there aren't too many people. These – this anxiety that it gives you, that as long as you are at home, it's different. But when you go out for necessities, or go to the hospital for a visit – in short, it's anxiety, that's it. You try to – every person you meet seems to be an enemy.” (Rosa, 72, F, Italian Native)     “I have a lot of fear, really a lot, and this has prevented me from going out and also from having a social life. My social life has almost disappeared, because partly the fear, partly my age, and so the result is that while before I used to go to concerts, I used to go to the movies, now we have – my husband and I – we have canceled everything, we don't go anymore, and so there is a lot of sadness.” (Alice, 75, F, Italian native)

Although some expressed feeling safer due to the vaccine, the fear induced by the virus was still present 2 years following the pandemic onset. Many Italian natives described the continued use of their phones to communicate with friends and family – more so than during pre-pandemic times – and this kept them company. Nonetheless, most expressed that while at the beginning they tried to accept the circumstances, the pandemic had started to weigh on them and negatively influence their wellbeing. Only one Italian native shared that the changes in social habits did not have a substantial impact on his wellbeing:

“[The pandemic] did not substantially change my life, nor my family's. Of course, there were occasions when we would have liked – during the holidays, for example – to spend more time with friends. We gave this up, and we think and hope that it was accepted by our friends. In any case, this withdrawal was nothing out the ordinary, so it was nothing irrational. Let's say that it did not affect our life, our wellbeing.” (Lorenzo, 74, M, Italian native)

Yet, even for a person like Lorenzo who estimates that his wellbeing was not lowered by the pandemic, his social habits have changed, which was observed for most of the Italian natives in Italy.

6 Discussion

The objective of this study was to provide insight into older adults' experiences of wellbeing as well as the coping strategies employed to overcome difficulties brought about by the pandemic, in particular social distancing. Our contribution to the existing literature is 4-fold: (1) we explored older adults' lived experiences not only through their recollection of the first months of the pandemic, but also through their narratives of wellbeing and coping 2 years after the pandemic onset, (2) we analyzed the experiences of older migrants, an underrepresented population in wellbeing and COVID-19-related research, (3) we compared the experiences of two groups – Swiss natives and Italian migrants – who lived the pandemic in the same context, and (4) we compared the experiences of older adults who were subject to strict containment measures – as was the case of Italian natives – to those of adults who benefitted from more lax restrictions.

The following section discusses the results of the qualitative interviews, as well as the study limitations and implications for future policy.

While many of our interviews highlight the negative consequences of the pandemic for older adults' wellbeing in Switzerland and Italy, they also emphasize the heterogeneity of older individuals' experiences, as well as their ability to adapt and cope with stressful situations. Swiss natives and Italian migrants lived the pandemic in the same context, one that did not impose strong stay-at-home order and allowed for a certain freedom of movement. Yet, we found pronounced differences in their descriptions of wellbeing, both in the narratives concerning the first lockdown in 2020, and in the narratives addressing the following years, until time of interview.

Most Swiss natives presented positive accounts of the lockdown period; their descriptions were often coupled with coping strategies they employed to address the COVID-19 containment measures. Consistently with previous studies on coping during the pandemic, in the first months of the pandemic Swiss older adults relied on hobbies to keep busy, closeness to nature, acceptance of the sanitary situation, and cognitive strategies to find the silver lining of living through a world-wide crisis ( Finlay et al., 2021 ; Fuller and Huseth-Zosel, 2021 ; Whitehead and Torossian, 2021 ; Brooks et al., 2022 ; Bustamante et al., 2022 ; Mau et al., 2022 ). Most participants described their wellbeing as unaffected even at the time of interview, 2 years after the pandemic onset. Although they described the inevitable decrease in physical contacts as bothersome, most were able to adopt behavioral strategies that involved vaccination and continued social distancing measures that kept them safe while fulfilling their social needs.

Even though Italian migrants experienced the pandemic in the same context as Swiss natives, their accounts of the lockdown and the following years were more heterogeneous. During the first months of the pandemic, they used coping strategies like those of the Swiss natives: they spent their time in nature, kept busy through hobbies, and they, too, positively referred to the freedom they felt due to Switzerland's relaxed containment measures. At this time, only some participants expressed feelings of sadness and loneliness. However, when reflecting on the entirety of the previous 2 years, most participants shared the negative impact of the pandemic on their wellbeing. Although many slowly resumed social activities at the time of interview, they evoked a continued sense of fear, distrust, and dejection. Many of their interviews demonstrated that the social distancing behaviors that allowed them to keep themselves physically safe diminished their wellbeing.

Due to the qualitative nature of this article, it is not possible to firmly assert that the different experiences of wellbeing among Swiss natives and Italian migrants are due to inequalities in reserves. However, we can posit that, at least for some Italian migrants in Switzerland, their ability to cope with the pandemic may have been partly influenced by their lower level of reserves in comparison to those of Swiss natives.

Most Italian migrants in our study migrated to Switzerland in the 1960s and 1970s, as part of the wave of labor migrants who moved from regions of Italy that lacked economic opportunities ( Bolzman and Vagni, 2018 ; Dones and Ciobanu, 2022 ). Quantitative studies have revealed that, compared to older Swiss natives, older Italian migrants in Switzerland have lower education levels, report themselves in worse health, and generally occupied lower-skilled jobs ( Bolzman and Vagni, 2018 ). For many, the migration to Switzerland as labor workers was followed by a lack of opportunities to improve their socio-economic circumstances, leaving them in worse situations in comparison to their Swiss counterparts. These disadvantaged conditions may have engendered psychological stresses that may have accumulated over the life course ( Dannefer, 2003 ; Settersten et al., 2020 ), thereby impacting migrants' ability to build the adequate reserves to successfully cope with life shocks.

In our qualitative sample of Italian migrants there is an overrepresentation of highly educated participants and of participants in a comfortable financial situation, as represented by the measure “making ends meet” in Table 1 ( Dones, 2023 ). However, on average they still have lower education levels than Swiss natives. Moreover, independently of current socioeconomic status, most participants spoke of the poverty and lack of jobs they experienced during their youth in Italy, which ultimately led them to migrate. In addition, when reflecting on other hardships encountered during their lifetimes, most cited the difficulties encountered when they migrated: discrimination, having to learn another language, detachment from family in Italy, and getting accustomed to a foreign country. Along with the disadvantaged socioeconomic conditions some participants experienced throughout the lifespan, most experienced migration-related stressors that, accumulated over the life course, may have impacted their capacity to cope with life shocks and with the pandemic in the same way that Swiss natives did. Moreover, the capacity to act in old age is dependent on the life course and the accumulation of reserves ( Settersten et al., 2020 ), making in this case a difference between the older Swiss and older migrants.

Although Italian migrants did employ similar coping mechanisms, for most, these coping strategies were not successful in combatting the negative impact of the pandemic on their experienced wellbeing. This finding is in line with research by Pan et al. (2021) , which revealed that coping strategies like increased telephone contact and increased participation in individual activities did not protect older Chinese migrants against loneliness.

Another possible explanation for the lower wellbeing expressed by Italian migrants compared to Swiss natives relates to transnational practices and attachment to the home country. Although participants did not mention their attachment to Italy when recounting their pandemic experiences, some did share the negative impact the Italian situation had on their wellbeing. Previous research stemming from the TransAge project has revealed that greater attachment to Italy correlates to greater worry about the COVID-19 pandemic ( Ludwig-Dehm et al., 2023 ), which may have thereby impacted Italian migrants' lived experiences. Similarly, we found one case of transnational attachment among Swiss natives. The ties to Barcelona led François to value the confinement situation in Switzerland.

In comparison to older adults residing in Switzerland, older Italian natives expressed more negative emotions and difficulties when describing both the first COVID-19 lockdown and the subsequent years. Most adopted coping strategies like acceptance and increased telephone use for social contact, but the fear brought about by the virus followed them until the time of interview. This prevented most from resuming social activities, despite being vaccinated, and many expressed continued feelings of sadness, loneliness, and anxiety.

When considering the particularly negative experiences of Italian natives in Italy, we cannot propose that these were related to the various types of reserves accumulated through life, as our participants led heterogeneous life-courses. Indeed, there may be a variety of influencing factors that have the potential to affect the wellbeing of older Italian adults. One of these factors could hypothetically relate to the strict confinement measures employed by the Italian government throughout the first 2 years of the pandemic. Research thus far has revealed that countries' stringency of physical distancing regulations was associated with higher incidence of loneliness and depression among older adults ( Atzendorf and Gruber, 2022 ; Mendez-Lopez et al., 2022 ). Additionally, a study on older adults in Italy showed that restrictive measures significantly impacted the quality of life, psychological wellbeing, and mobility of older adults ( Tosato et al., 2022 ). Although no studies have yet been published on the long-term consequences of strict containment measures, our exploratory results could point to the negative impact of such regulations on older adults' experiences of wellbeing. However, this is simply a theoretical proposition and further studies on the subject are needed to firmly establish a correlation between stringency of confinement regulations and wellbeing.

Moreover, Italian natives relied on telephone communication as a coping mechanism more than the other two groups. While staying in touch with family and friends through phone and other media use has been correlated with life satisfaction during the first semi-lockdown in Switzerland ( Dones et al., 2022 ), studies found that non-personal communication does not substitute face-to-face interactions and it is not a protective strategy against loneliness among older adults ( Pan et al., 2021 ; König and Isengard, 2023 ). Further research should thus address the effectiveness of different coping strategies in times of crisis.

6.1 Limitations, strengths, and suggestions for future research

This study does not come without limitations. Due to the qualitative nature of the research and the relatively small sample size, results cannot be generalized even though saturation of responses was reached. In addition, our study did not explore the experiences of many people who lived alone during the pandemic, a population that might have been particularly at risk of social isolation. Similarly, there is a possibility that older adults with lower levels of wellbeing may not have been willing to participate to the research, although some research participants shared their difficulties and negative experiences of the pandemic. Lastly, to be able to better understand the role of reserves in older adults' experiences of the pandemic, longitudinal, quantitative data would be necessary.

Nonetheless, this article sheds light on several aspects. First, despite the homogeneous representation of older adults as frail and vulnerable ( Petretto and Pili, 2020 ; Ayalon et al., 2021 ; Maggiori et al., 2022 ), the pandemic impact on wellbeing is not the same for all older adults, as demonstrated by emerging studies ( Wettstein et al., 2022a , b ) and by the different experiences of this article's older populations. Second, despite the employment of coping strategies used by all participants, their effectiveness in mediating the long-term impact of the pandemic on experiences of wellbeing differed among groups. Third, the long-term impact of the pandemic and the various containment strategies needs further examination. As the case of Italian migrants in Switzerland shows, some older migrants experienced the beginning of the pandemic in quite positive ways, but their narratives of their situation 2 years after the pandemic onset showed an overall negative effect on their wellbeing.

The share of older adults in Europe continues to increase ( Eurostat, 2023 ), as does the share of older migrants ( UNDESA, 2020 ). The advancements of the last few decades have reduced the dependence of older adults and have increased life expectancy. At the same time, social inequalities and inter-individual diversity make of today's older adults an increasingly heterogeneous group ( Oris et al., 2020 ). The consideration of this heterogeneity should be at the core of not only scientific research, but also of policy interventions, as grouping all older adults under the “vulnerable and frail” umbrella propagates against narratives that can lead to increased psychological distress and negative self-perceptions of aging ( Losada-Baltar et al., 2021 ; Derrer-Merk et al., 2022a , b ).

To account for the diversity in older adults' lives, research on the long-term impact of the pandemic should adopt a life-course approach to further analyze how differing trajectories engender situations of resilience or vulnerability. Given the increase of share of older migrants, their underrepresentation in COVID-19 and wellbeing research, and the possible long-term effects of having a migration background, special consideration should be allotted to them. Moreover, studies should further address the effectiveness of coping strategies among different populations. Lastly, in cases of future health crises, governments should have an increased regard for the negative consequences of stringent confinement measures, as social isolation and physical inactivity among older adults are correlated with increased hospitalization, depression, cognitive impairment, and reduced quality of life ( Cacioppo et al., 2010 ; Cacioppo and Cacioppo, 2014 ; Ozemek et al., 2019 ).

Data availability statement

The datasets presented in this article are not readily available because the qualitative interviews analyzed in this study are not publicly available. For now, they are available from RC on reasonable request. Requests to access the datasets should be directed to RC, oana.ciobanu@hetsl.ch .

Ethics statement

The studies involving humans were approved by the Ethics Committee of the Faculty of Social Sciences of the University of Geneva. The studies were conducted in accordance with the local legislation and institutional requirements. Written informed consent for participation was not required from the participants or the participants' legal guardians/next of kin because participation in the study was voluntary, and all participants gave oral consent to be interviewed and recorded.

Author contributions

ID drafted the interview guidelines, carried out the data collection and analysis, and was the major contributor in writing the manuscript. RC supervised the project, reviewed and approved the interview guidelines, provided article references, read parts of the interviews, and contributed to the discussion and conclusion. All authors read and approved the final manuscript.

This work was funded by the Swiss National Science Foundation through the Professorship Grant “Transnational Aging among Older Migrants and Natives: A Strategy to Overcome Vulnerability” (Grant Number PP00P1_179077/1).

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Publisher's note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

1. ^ Of these phone interviews, one was done through WhatsApp audio, the rest through the regular phone line.

2. ^ The participant is referring to the war between Russia and Ukraine, which had just begun at the time of interview.

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Keywords: migration, coping, subjective wellbeing, health crisis, vulnerability

Citation: Dones I and Ciobanu RO (2024) Older adults' experiences of wellbeing during the COVID-19 pandemic: a comparative qualitative study in Italy and Switzerland. Front. Sociol. 9:1243760. doi: 10.3389/fsoc.2024.1243760

Received: 21 June 2023; Accepted: 15 April 2024; Published: 01 May 2024.

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Copyright © 2024 Dones and Ciobanu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY) . The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Iuna Dones, iuna.dones@hesge.ch

This article is part of the Research Topic

Community Series in Mental Illness, Culture, and Society: Dealing with the COVID-19 Pandemic, volume VIII