define covid 19 essay

• History & Society
• Science & Tech
• Biographies
• Animals & Nature
• Geography & Travel
• Arts & Culture
• Games & Quizzes
• On This Day
• One Good Fact
• New Articles
• Lifestyles & Social Issues
• Philosophy & Religion
• Politics, Law & Government
• World History
• Health & Medicine
• Browse Biographies
• Birds, Reptiles & Other Vertebrates
• Bugs, Mollusks & Other Invertebrates
• Environment
• Fossils & Geologic Time
• Entertainment & Pop Culture
• Sports & Recreation
• Visual Arts
• Demystified
• Image Galleries
• Infographics
• Top Questions
• Britannica Kids
• Saving Earth
• Space Next 50
• Student Center

• Does the virus that causes COVID-19 belong to the coronavirus family?

Our editors will review what you’ve submitted and determine whether to revise the article.

• Frontiers - ABO Blood System and COVID-19 Susceptibility: Anti-A and Anti-B antibodies are the key points
• Centers for Disease Control and Prevention - COVID-19
• Healthline - What is Herd Immunity and Could it Help Prevent COVID-19?
• Centers for Disease Control and Prevention - Coronavirus Disease 2019
• COVID-19 - Student Encyclopedia (Ages 11 and up)

Recent News

COVID-19 , highly contagious respiratory illness , the cause of the COVID-19 pandemic . COVID-19 was first detected in 2019 in Wuhan , China . A large proportion of infections in China were undocumented before travel restrictions and other control measures were implemented in late January 2020. As a result, COVID-19 very quickly spread to countries worldwide, giving rise to a multiyear pandemic that resulted in millions of deaths. The pandemic also spurred a revolution in business and education, spawning a reliance on distance learning and work -at-home arrangements and the rise of videoconferencing platforms such as Zoom , which became one of the most downloaded applications worldwide and a household word.

• Read more about the impact of the COVID-19 pandemic.

COVID-19 is caused by a coronavirus known as severe acute respiratory syndrome coronavirus 2 ( SARS-CoV-2 ). The disease is transmitted primarily through contact with infectious material, particularly respiratory droplets that enter the environment when an infected person sneezes or coughs. Individuals nearby may inhale or come into contact with these droplets, resulting in disease transmission. Infection may also occur when a person comes into contact with a contaminated surface and then touches his or her mouth, nose , or eyes. Individuals at greatest risk of COVID-19 infection include older adults and persons with chronic illness, largely because of weakened immune function.

COVID-19 is characterized by a variety of symptoms, including fever , cough , congestion, fatigue , shortness of breath, headache , sore throat , nausea or vomiting, loss of smell or taste, and body aches. COVID-19 may progress to severe respiratory illness, with symptoms of chest pain and extreme difficulty in breathing, requiring hospitalization. Some COVID-19 patients who are hospitalized further develop neurological symptoms, including severe fatigue and altered consciousness . Delirium has been observed in many of these patients as well, possibly as a side effect of medication. Delirium and lingering psychological issues, including depression and anxiety , can prolong and complicate recovery.

There is no cure for COVID-19. However, different types of drugs have been used to treat infection and to reduce the severity of the disease. Examples include antiviral drugs , such as remdesivir , molnupiravir, and combined ritonavir and nirmatrelvir; a drug used for pancreatic inflammation called camostat mesilate; and various therapeutic monoclonal antibodies , such as REGEN-COV (casirivimab and imdevimab). COVID-19 vaccines , which became available in late 2020, are highly effective in protecting against severe illness and in limiting the spread of the disease; immunity can be further bolstered through subsequent booster doses of vaccine . Risk of disease transmission can be reduced by measures such as social distancing, disinfection of surfaces, and universal community use of face masks. Self-isolation and self-quarantine are other ways in which the spread of COVID-19 can be stopped.

Survivors of severe COVID-19, particularly those who were hospitalized, are likely to suffer long-term effects. Individuals who required mechanical ventilation might never fully recover; ventilator use is associated with severe muscle atrophy and weakness, which significantly impact survival and quality of life .

The ongoing spread of COVID-19 has been fueled by the emergence of variants in evolving lineages of SARS-CoV-2. Such variants generally carry mutations that strengthen characteristics such as the virus’s ability to infect individuals (including individuals who are vaccinated and who previously had COVID-19), to cause severe disease, and to potentially escape certain treatments. There are numerous variants, the most notable of which is Omicron , which was first detected in Botswana in November 2021 and quickly became the primary circulating strain globally. Omicron spawned multiple sublineages of concern, including BA.4 and BA.5, which are highly infectious, and BA.2, which gave rise to XBB.1.5—a highly transmissible variant, noted for its heightened ability to bind to cells and to replicate.

Masks Strongly Recommended but Not Required in Maryland

Respiratory viruses continue to circulate in Maryland, so masking remains strongly recommended when you visit Johns Hopkins Medicine clinical locations in Maryland. To protect your loved one, please do not visit if you are sick or have a COVID-19 positive test result. Get more resources on masking and COVID-19 precautions .

• Vaccines  
• Masking Guidelines
• Visitor Guidelines  

What Is Coronavirus?

Coronaviruses are a type of virus. There are many different kinds, and some cause disease. A coronavirus identified in 2019, SARS-CoV-2, has caused a pandemic of respiratory illness, called COVID-19.

What You Need to Know COVID-19

• COVID-19 is the disease caused by SARS-CoV-2, the coronavirus that emerged in December 2019.
• COVID-19 can be severe, and has caused millions of deaths around the world as well as lasting health problems in some who have survived the illness.
• The coronavirus can be spread from person to person. It is diagnosed with a test.
• The best way to protect yourself is to get vaccinated and boosted when you are eligible, follow testing guidelines, wear a mask, wash your hands and practice physical distancing.

How does the coronavirus spread?

As of now, researchers know that the coronavirus is spread through droplets and virus particles released into the air when an infected person breathes, talks, laughs, sings, coughs or sneezes. Larger droplets may fall to the ground in a few seconds, but tiny infectious particles can linger in the air and accumulate in indoor places, especially where many people are gathered and there is poor ventilation. This is why mask-wearing, hand hygiene and physical distancing are essential to preventing COVID-19.

How did the coronavirus start?

The first case of COVID-19 was reported Dec. 1, 2019, and the cause was a then-new coronavirus later named SARS-CoV-2. SARS-CoV-2 may have originated in an animal and changed (mutated) so it could cause illness in humans. In the past, several infectious disease outbreaks have been traced to viruses originating in birds, pigs, bats and other animals that mutated to become dangerous to humans. Research continues, and more study may reveal how and why the coronavirus evolved to cause pandemic disease.

What is the incubation period for COVID-19?

Symptoms show up in people within two to 14 days of exposure to the virus. A person infected with the coronavirus is contagious to others for up to two days before symptoms appear, and they remain contagious to others for 10 to 20 days, depending upon their immune system and the severity of their illness. 

What have you learned about coronavirus in the last six months?

Infectious disease expert Lisa Maragakis explains the advances in COVID-19 treatments and how knowledge of COVID-19 can assist in preventing further spread of the virus.

What are symptoms of coronavirus?

COVID-19 symptoms include:

• Fever or chills
• Shortness of breath or difficulty breathing
• Muscle or body aches
• Sore throat
• New loss of taste or smell
• New fatigue
• Nausea or vomiting
• Congestion or runny nose

Some people infected with the coronavirus have mild COVID-19 illness, and others have no symptoms at all. In some cases, however, COVID-19 can lead to respiratory failure, lasting  lung  and  heart muscle damage ,  nervous system problems ,  kidney failure  or death.

If you have a fever or any of the symptoms listed above, call your doctor or a health care provider and explain your symptoms over the phone before going to the doctor’s office, urgent care facility or emergency room. Here are suggestions  if you feel sick and are concerned you might have COVID-19 .

CALL 911 if you have a medical emergency such as severe shortness of breath or difficulty breathing.

Learn more about COVID-19 symptoms .

How is COVID-19 diagnosed?

COVID-19 is diagnosed through a test. Diagnosis by examination alone is difficult since many COVID-19 signs and symptoms can be caused by other illnesses. Some people with the coronavirus do not have symptoms at all.  Learn more about COVID-19 testing .

How is COVID-19 treated?

Treatment for COVID-19 depends on the severity of the infection. For milder illness, resting at home and taking medicine to reduce fever is often sufficient. More severe cases may require hospitalization, with treatment that might include intravenous medications, supplemental oxygen, assisted ventilation and other supportive measures

How do you protect yourself from this?

There are several COVID-19 vaccines recommended by the CDC . It is also important to receive a booster when you are eligible .

In addition, it helps to keep up with other safety precautions, such as following testing guidelines, wearing a mask, washing your hands and practicing physical distancing.

Does COVID-19 cause death?

Yes, severe COVID-19 can be fatal. For updates of coronavirus infections, deaths and vaccinations worldwide, see the  Coronavirus COVID-19 Global Cases  map developed by the Johns Hopkins Center for Systems Science and Engineering.

Two COVID-19 vaccines – Pfizer and Moderna - have been fully approved by the FDA and recommended by the CDC as highly effective in preventing serious disease, hospitalization and death from COVID-19.

The CDC notes that in most situations the two mRNA vaccines from Pfizer and Moderna are preferred over the Johnson & Johnson vaccine due to a risk of serious adverse events .

It is also important to receive a booster when eligible. You can get any of these three authorized or approved vaccines, but the CDC explains that Pfizer and Moderna are preferred in most situations.

Why is it called coronavirus?

Coronaviruses are named for their appearance: “corona” means “crown.” The virus’s outer layers are covered with spike proteins that surround them like a crown.

Is this coronavirus different from SARS?

SARS  stands for severe acute respiratory syndrome. In 2003, an outbreak of SARS affected people in several countries before ending in 2004. The coronavirus that causes COVID-19 is similar to the one that caused the 2003 SARS outbreak.

Since the 2019 coronavirus is related to the original coronavirus that caused SARS and can also cause severe acute respiratory syndrome, there is “SARS” in its name: SARS-CoV-2. Much is still unknown about these viruses, but SARS-CoV-2 spreads faster and farther than the 2003 SARS-CoV-1 virus. This is likely because of how easily it is transmitted person to person, even from asymptomatic carriers of the virus.

Are there different variants of this coronavirus?

Yes, there are different variants of this coronavirus. Like other viruses, the coronavirus that causes COVID-19 can change (mutate). Mutations may enable the coronavirus to spread faster from person to person as in the case of the delta and omicron variants. More infections can result in more people getting very sick and also create more opportunity for the virus to develop further mutations. Read more about  coronavirus variants .

Coronavirus: What do I do if I Feel Sick?

If you are concerned that you may have COVID-19, follow these steps to help protect your health and the health of others.

About Coronaviruses

• Coronaviruses are common in different animals. Rarely, an animal coronavirus can infect humans.
• There are many different kinds of coronaviruses. Some of them can cause colds or other mild respiratory (nose, throat, lung) illnesses.
• Other coronaviruses can cause serious diseases, including severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS).

Coronavirus (COVID-19)

What you need to know from Johns Hopkins Medicine.

What Activities Are Safe During the Coronavirus Pandemic?

Don't Avoid Your Doctor During the Coronavirus Pandemic

Coronavirus Diagnosis: What Should I Expect?

Related Topics

• Infectious Diseases

An official website of the United States government

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

• Publications
• Account settings

Preview improvements coming to the PMC website in October 2024. Learn More or Try it out now .

• Advanced Search
• Journal List
• v.24; 2020 Jul

COVID-19 infection: Origin, transmission, and characteristics of human coronaviruses

Muhammad adnan shereen.

a The Department of Cerebrovascular Diseases, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, PR China

b State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, PR China

Suliman Khan

Abeer kazmi.

c College of Life Sciences, Wuhan University, Wuhan, PR China

Nadia Bashir

Rabeea siddique, graphical abstract.

The coronavirus disease 19 (COVID-19) is a highly transmittable and pathogenic viral infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which emerged in Wuhan, China and spread around the world. Genomic analysis revealed that SARS-CoV-2 is phylogenetically related to severe acute respiratory syndrome-like (SARS-like) bat viruses, therefore bats could be the possible primary reservoir. The intermediate source of origin and transfer to humans is not known, however, the rapid human to human transfer has been confirmed widely. There is no clinically approved antiviral drug or vaccine available to be used against COVID-19. However, few broad-spectrum antiviral drugs have been evaluated against COVID-19 in clinical trials, resulted in clinical recovery. In the current review, we summarize and comparatively analyze the emergence and pathogenicity of COVID-19 infection and previous human coronaviruses severe acute respiratory syndrome coronavirus (SARS-CoV) and middle east respiratory syndrome coronavirus (MERS-CoV). We also discuss the approaches for developing effective vaccines and therapeutic combinations to cope with this viral outbreak.

Introduction

Coronaviruses belong to the Coronaviridae family in the Nidovirales order. Corona represents crown-like spikes on the outer surface of the virus; thus, it was named as a coronavirus. Coronaviruses are minute in size (65–125 nm in diameter) and contain a single-stranded RNA as a nucleic material, size ranging from 26 to 32kbs in length ( Fig. 1 ). The subgroups of coronaviruses family are alpha (α), beta (β), gamma (γ) and delta (δ) coronavirus. The severe acute respiratory syndrome coronavirus (SARS-CoV), H5N1 influenza A, H1N1 2009 and Middle East respiratory syndrome coronavirus (MERS-CoV) cause acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) which leads to pulmonary failure and result in fatality. These viruses were thought to infect only animals until the world witnessed a severe acute respiratory syndrome (SARS) outbreak caused by SARS-CoV, 2002 in Guangdong, China [1] . Only a decade later, another pathogenic coronavirus, known as Middle East respiratory syndrome coronavirus (MERS-CoV) caused an endemic in Middle Eastern countries [2] .

Structure of respiratory syndrome causing human coronavirus.

Recently at the end of 2019, Wuhan an emerging business hub of China experienced an outbreak of a novel coronavirus that killed more than eighteen hundred and infected over seventy thousand individuals within the first fifty days of the epidemic. This virus was reported to be a member of the β group of coronaviruses. The novel virus was named as Wuhan coronavirus or 2019 novel coronavirus (2019-nCov) by the Chinese researchers. The International Committee on Taxonomy of Viruses (ICTV) named the virus as SARS-CoV-2 and the disease as COVID-19 [3] , [4] , [5] . In the history, SRAS-CoV (2003) infected 8098 individuals with mortality rate of 9%, across 26 contries in the world, on the other hand, novel corona virus (2019) infected 120,000 induviduals with mortality rate of 2.9%, across 109 countries, till date of this writing. It shows that the transmission rate of SARS-CoV-2 is higher than SRAS-CoV and the reason could be genetic recombination event at S protein in the RBD region of SARS-CoV-2 may have enhanced its transmission ability. In this review article, we discuss the origination of human coronaviruses briefly. We further discuss the associated infectiousness and biological features of SARS and MERS with a special focus on COVID-19.

Comparative analysis of emergence and spreading of coronaviruses

In 2003, the Chinese population was infected with a virus causing Severe Acute Respiratory Syndrome (SARS) in Guangdong province. The virus was confirmed as a member of the Beta-coronavirus subgroup and was named SARS-CoV [6] , [7] . The infected patients exhibited pneumonia symptoms with a diffused alveolar injury which lead to acute respiratory distress syndrome (ARDS). SARS initially emerged in Guangdong, China and then spread rapidly around the globe with more than 8000 infected persons and 776 deceases. A decade later in 2012, a couple of Saudi Arabian nationals were diagnosed to be infected with another coronavirus. The detected virus was confirmed as a member of coronaviruses and named as the Middle East Respiratory Syndrome Coronavirus (MERS-CoV). The World health organization reported that MERS-coronavirus infected more than 2428 individuals and 838 deaths [8] . MERS-CoV is a member beta-coronavirus subgroup and phylogenetically diverse from other human-CoV. The infection of MERS-CoV initiates from a mild upper respiratory injury while progression leads to severe respiratory disease. Similar to SARS-coronavirus, patients infected with MERS-coronavirus suffer pneumonia, followed by ARDS and renal failure [9] .

Recently, by the end of 2019, WHO was informed by the Chinese government about several cases of pneumonia with unfamiliar etiology. The outbreak was initiated from the Hunan seafood market in Wuhan city of China and rapidly infected more than 50 peoples. The live animals are frequently sold at the Hunan seafood market such as bats, frogs, snakes, birds, marmots and rabbits [10] . On 12 January 2020, the National Health Commission of China released further details about the epidemic, suggested viral pneumonia [10] . From the sequence-based analysis of isolates from the patients, the virus was identified as a novel coronavirus. Moreover, the genetic sequence was also provided for the diagnosis of viral infection. Initially, it was suggested that the patients infected with Wuhan coronavirus induced pneumonia in China may have visited the seafood market where live animals were sold or may have used infected animals or birds as a source of food. However, further investigations revealed that some individuals contracted the infection even with no record of visiting the seafood market. These observations indicated a human to the human spreading capability of this virus, which was subsequently reported in more than 100 countries in the world. The human to the human spreading of the virus occurs due to close contact with an infected person, exposed to coughing, sneezing, respiratory droplets or aerosols. These aerosols can penetrate the human body (lungs) via inhalation through the nose or mouth ( Fig. 2 ) [11] , [12] , [13] , [14] .

The key reservoirs and mode of transmission of coronaviruses (suspected reservoirs of SARS-CoV-2 are red encircled); only α and β coronaviruses have the ability to infect humans, the consumption of infected animal as a source of food is the major cause of animal to human transmission of the virus and due to close contact with an infected person, the virus is further transmitted to healthy persons. Dotted black arrow shows the possibility of viral transfer from bat whereas the solid black arrow represent the confirmed transfer. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Primary reservoirs and hosts of coronaviruses

The source of origination and transmission are important to be determined in order to develop preventive strategies to contain the infection. In the case of SARS-CoV, the researchers initially focused on raccoon dogs and palm civets as a key reservoir of infection. However, only the samples isolated from the civets at the food market showed positive results for viral RNA detection, suggesting that the civet palm might be secondary hosts [15] . In 2001 the samples were isolated from the healthy persons of Hongkong and the molecular assessment showed 2.5% frequency rate of anti-bodies against SARS-coronavirus. These indications suggested that SARS-coronavirus may be circulating in humans before causing the outbreak in 2003 [16] . Later on, Rhinolophus bats were also found to have anti-SARS-CoV antibodies suggesting the bats as a source of viral replication [17] . The Middle East respiratory syndrome (MERS) coronavirus first emerged in 2012 in Saudi Arabia [9] . MERS-coronavirus also pertains to beta-coronavirus and having camels as a zoonotic source or primary host [18] . In a recent study, MERS-coronavirus was also detected in Pipistrellus and Perimyotis bats [19] , proffering that bats are the key host and transmitting medium of the virus [20] , [21] . Initially, a group of researchers suggested snakes be the possible host, however, after genomic similarity findings of novel coronavirus with SARS-like bat viruses supported the statement that not snakes but only bats could be the key reservoirs ( Table 1 ) [22] , [23] . Further analysis of homologous recombination revealed that receptor binding spike glycoprotein of novel coronavirus is developed from a SARS-CoV (CoVZXC21 or CoVZC45) and a yet unknown Beta-CoV [24] . Nonetheless, to eradicate the virus, more work is required to be done in the aspects of the identification of the intermediate zoonotic source that caused the transmission of the virus to humans.

Comparative analysis of biological features of SARS-CoV and SARS-CoV-2.

Key features and entry mechanism of human coronaviruses

All coronaviruses contain specific genes in ORF1 downstream regions that encode proteins for viral replication, nucleocapsid and spikes formation [25] . The glycoprotein spikes on the outer surface of coronaviruses are responsible for the attachment and entry of the virus to host cells ( Fig. 1 ). The receptor-binding domain (RBD) is loosely attached among virus, therefore, the virus may infect multiple hosts [26] , [27] . Other coronaviruses mostly recognize aminopeptidases or carbohydrates as a key receptor for entry to human cells while SARS-CoV and MERS-CoV recognize exopeptidases [2] . The entry mechanism of a coronavirus depends upon cellular proteases which include, human airway trypsin-like protease (HAT), cathepsins and transmembrane protease serine 2 (TMPRSS2) that split the spike protein and establish further penetration changes [28] , [29] . MERS-coronavirus employs dipeptidyl peptidase 4 (DPP4), while HCoV-NL63 and SARS-coronavirus require angiotensin-converting enzyme 2 (ACE2) as a key receptor [2] , [26] .

SARS-CoV-2 possesses the typical coronavirus structure with spike protein and also expressed other polyproteins, nucleoproteins, and membrane proteins, such as RNA polymerase, 3-chymotrypsin-like protease, papain-like protease, helicase, glycoprotein, and accessory proteins [30] , [31] . The spike protein of SARS-CoV-2 contains a 3-D structure in the RBD region to maintain the van der Waals forces [32] . The 394 glutamine residue in the RBD region of SARS-CoV-2 is recognized by the critical lysine 31 residue on the human ACE2 receptor [33] . The entire mechanism of pathogenicity of SARS-CoV-2, from attachment to replication is well mentioned in Fig. 3 .

The life cycle of SARS-CoV-2 in host cells; begins its life cycle when S protein binds to the cellular receptor ACE2. After receptor binding, the conformation change in the S protein facilitates viral envelope fusion with the cell membrane through the endosomal pathway. Then SARS-CoV-2 releases RNA into the host cell. Genome RNA is translated into viral replicase polyproteins pp1a and 1ab, which are then cleaved into small products by viral proteinases. The polymerase produces a series of subgenomic mRNAs by discontinuous transcription and finally translated into relevant viral proteins. Viral proteins and genome RNA are subsequently assembled into virions in the ER and Golgi and then transported via vesicles and released out of the cell. ACE2, angiotensin-converting enzyme 2; ER, endoplasmic reticulum; ERGIC, ER–Golgi intermediate compartment.

Genomic variations in SARS-CoV-2

The genome of the SARS-CoV-2 has been reported over 80% identical to the previous human coronavirus (SARS-like bat CoV) [34] . The Structural proteins are encoded by the four structural genes, including spike (S), envelope (E), membrane (M) and nucleocapsid (N) genes. The orf1ab is the largest gene in SARS-CoV-2 which encodes the pp1ab protein and 15 nsps. The orf1a gene encodes for pp1a protein which also contains 10 nsps [34] , [35] , [36] . According to the evolutionary tree, SARS-CoV-2 lies close to the group of SARS-coronaviruses [37] , [38] ( Fig. 5 ). Recent studies have indicated notable variations in SARS-CoV and SARS-CoV-2 such as the absence of 8a protein and fluctuation in the number of amino acids in 8b and 3c protein in SARS-CoV-2 [34] ( Fig. 4 ). It is also reported that Spike glycoprotein of the Wuhan coronavirus is modified via homologous recombination. The spike glycoprotein of SARS-CoV-2 is the mixture of bat SARS-CoV and a not known Beta-CoV [38] . In a fluorescent study, it was confirmed that the SARS-CoV-2 also uses the same ACE2 (angiotensin-converting enzyme 2) cell receptor and mechanism for the entry to host cell which is previously used by the SARS-CoV [39] , [40] . The single N501T mutation in SARS-CoV-2's Spike protein may have significantly enhanced its binding affinity for ACE2 [33] .

Betacoronaviruses genome organization; The Betacoronavirus for human (SARS-CoV-2, SARS-CoV and MERS-CoV) genome comprises of the 5′-untranslated region (5′-UTR), open reading frame (orf) 1a/b (green box) encoding non-structural proteins (nsp) for replication, structural proteins including spike (blue box), envelop (maroon box), membrane (pink box), and nucleocapsid (cyan box) proteins, accessory proteins (light gray boxes) such as orf 3, 6, 7a, 7b, 8 and 9b in the SARS-CoV-2 genome, and the 3′-untranslated region (3′-UTR). The doted underlined in red are the protein which shows key variation between SARS-CoV-2 and SARS-CoV. The length of nsps and orfs are not drawn in scale. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Phylogenetic tree of coronaviruses (content in red is the latest addition of newly emerged SARS-CoV-2 and WSFMP Wuhan-Hu-1 is used as a reference in the tree); The phylogenetic tree showing the relationship of Wuhan-Hu-1 (denoted as red) to selected coronavirus is based on nucleotide sequences of the complete genome. The viruses are grouped into four genera (prototype shown): Alphacoronavirus (sky blue), Betacoronavirus (pink), Gammacoronavirus (green) and Deltacoronavirus (light blue). Subgroup clusters are labeled as 1a and 1b for the Alphacoronavirus and 2a, 2b, 2c, and 2d for the Betacoronavirus. This tree is based on the published trees of Coronavirinae [3] , [41] and reconstructed with sequences of the complete RNA- dependent RNA polymerase- coding region of the representative novel coronaviruses (maximum likelihood method using MEGA 7.2 software). severe acute respiratory syndrome coronavirus (SARS- CoV); SARS- related coronavirus (SARSr- CoV); the Middle East respiratory syndrome coronavirus (MERS- CoV); porcine enteric diarrhea virus (PEDV); Wuhan seafood market pneumonia (Wuhan-Hu-1). Bat CoV RaTG13 Showed high sequence identity to SARS-CoV-2 [42] . (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

The major obstacle in research progress

Animal models play a vital role to uncover the mechanisms of viral pathogenicity from the entrance to the transmission and designing therapeutic strategies. Previously, to examine the replication of SARS-CoV, various animal models were used which showed the symptoms of severe infection [43] . In contrast to SARS-CoV, no MERS-CoV pathogenesis was observed in small animals. Mice are not vulnerable to infection by MERS-coronavirus due to the non-compatibility of the DPP4 receptor [44] . As the entire genome of the 2019-novel coronavirus is more than 80% similar to the previous human SARS-like bat CoV, previously used animal models for SARS-CoV can be utilized to study the infectious pathogenicity of SARS-CoV-2. The human ACE2 cell receptor is recognized by both SARS and Novel coronaviruses. Conclusively, TALEN or CRISPR-mediated genetically modified hamsters or other small animals can be utilized for the study of the pathogenicity of novel coronaviruses. SARS-CoV has been reported to replicate and cause severe disease in Rats (F344), where the sequence analysis revealed a mutation at spike glycoprotein [45] . Thus, it could be another suitable option to develop spike glycoprotein targeting therapeutics against novel coronaviruses. Recently, mice models and clinical isolates were used to develop any therapeutic strategy against SARS-CoV-2 induced COVID-19 [46] , [47] . In a similar study, artificial intelligence prediction was used to investigate the inhibitory role of the drug against SARS-CoV-2 [48] . SARS-CoV-2 infected patients were also used to conduct randomized clinical trials [46] , [49] , [50] . It is now important that the scientists worldwide collaborate the design a suitable model and investigate the in vivo mechanisms associated with pathogenesis of SARS-CoV-2.

Potential therapeutic strategies against COVID-19

Initially, interferons-α nebulization, broad-spectrum antibiotics, and anti-viral drugs were used to reduce the viral load [49] , [51] , [52] , however, only remdesivir has shown promising impact against the virus [53] . Remdesivir only and in combination with chloroquine or interferon beta significantly blocked the SARS-CoV-2 replication and patients were declared as clinically recovered [46] , [50] , [52] . Various other anti-virals are currently being evaluated against infection. Nafamostat, Nitazoxanide, Ribavirin, Penciclovir, Favipiravir, Ritonavir, AAK1, Baricitinib, and Arbidol exhibited moderate results when tested against infection in patients and in-vitro clinical isolates [46] , [48] , [50] , [52] . Several other combinations, such as combining the antiviral or antibiotics with traditional Chinese medicines were also evaluated against SARS-CoV-2 induced infection in humans and mice [46] . Recently in Shanghai, doctors isolated the blood plasma from clinically recovered patients of COVID-19 and injected it in the infected patients who showed positive results with rapid recovery [54] . In a recent study, it was identified that monoclonal antibody (CR3022) binds with the spike RBD of SARS-CoV-2. This is likely due to the antibody’s epitope not overlapping with the divergent ACE2 receptor-binding motif. CR3022 has the potential to be developed as a therapeutic candidate, alone or in combination with other neutralizing antibodies for the prevention and treatment of COVID-19 infection [55] .

Vaccines for SARS-CoV-2

There is no available vaccine against COVID-19, while previous vaccines or strategies used to develop a vaccine against SARS-CoV can be effective. Recombinant protein from the Urbani (AY278741) strain of SARS-CoV was administered to mice and hamsters, resulted in the production of neutralizing antibodies and protection against SARS-CoV [56] , [57] . The DNA fragment, inactivated whole virus or live-vectored strain of SARS-CoV (AY278741), significantly reduced the viral infection in various animal models [58] , [59] , [60] , [61] , [62] , [63] . Different other strains of SARS-CoV were also used to produce inactivated or live-vectored vaccines which efficiently reduced the viral load in animal models. These strains include, Tor2 (AY274119) [64] , [65] , Utah (AY714217) [66] , FRA (AY310120) [59] , HKU-39849 (AY278491) [57] , [67] , BJ01 (AY278488) [68] , [69] , NS1 (AY508724) [70] , ZJ01 (AY297028) [70] , GD01 (AY278489) [69] and GZ50 (AY304495) [71] . However, there are few vaccines in the pipeline against SARS-CoV-2. The mRNA based vaccine prepared by the US National Institute of Allergy and Infectious Diseases against SARS-CoV-2 is under phase 1 trial [72] . INO-4800-DNA based vaccine will be soon available for human testing [73] . Chinese Centre for Disease Control and Prevention (CDC) working on the development of an inactivated virus vaccine [74] , [75] . Soon mRNA based vaccine’s sample (prepared by Stermirna Therapeutics) will be available [76] . GeoVax-BravoVax is working to develop a Modified Vaccina Ankara (MVA) based vaccine [77] . While Clover Biopharmaceuticals is developing a recombinant 2019-nCoV S protein subunit-trimer based vaccine [78] .

Although research teams all over the world are working to investigate the key features, pathogenesis and treatment options, it is deemed necessary to focus on competitive therapeutic options and cross-resistance of other vaccines. For instance, there is a possibility that vaccines for other diseases such as rubella or measles can create cross-resistance for SARS-CoV-2. This statement of cross-resistance is based on the observations that children in china were found less vulnerable to infection as compared to the elder population, while children are being largely vaccinated for measles in China.

Conclusion and perspective

The novel coronavirus originated from the Hunan seafood market at Wuhan, China where bats, snakes, raccoon dogs, palm civets, and other animals are sold, and rapidly spread up to 109 countries. The zoonotic source of SARS-CoV-2 is not confirmed, however, sequence-based analysis suggested bats as the key reservoir. DNA recombination was found to be involved at spike glycoprotein which assorted SARS-CoV (CoVZXC21 or CoVZC45) with the RBD of another Beta CoV, thus could be the reason for cross-species transmission and rapid infection. According to phylogenetic trees, SARS-CoV is closer to SARS-like bat CoVs. Until now, no promising clinical treatments or prevention strategies have been developed against human coronaviruses. However, the researchers are working to develop efficient therapeutic strategies to cope with the novel coronaviruses. Various broad-spectrum antivirals previously used against influenza, SARS and MERS coronaviruses have been evaluated either alone or in combinations to treat COVID-19 patients, mice models, and clinical isolates. Remdesivir, Lopinavir, Ritonavir, and Oseltamivir significantly blocked the COVID-19 infection in infected patients. It can be cocluded that the homologus recombination event at the S protein of RBD region enhanced the transmission ability of the virus. While the decision of bring back the nationals from infected area by various countries and poor screening of passengers, become the leading cause of spreading virus in others countries.

Most importantly, human coronaviruses targeting vaccines and antiviral drugs should be designed that could be used against the current as well as future epidemics. There are many companies working for the development of effective SARS-CoV-2 vaccines, such as Moderna Therapeutics, Inovio Pharmaceuticals, Novavax, Vir Biotechnology, Stermirna Therapeutics, Johnson & Johnson, VIDO-InterVac, GeoVax-BravoVax, Clover Biopharmaceuticals, CureVac, and Codagenix. But there is a need for rapid human and animal-based trails as these vaccines still require 3–10 months for commercialization. There must be a complete ban on utilizing wild animals and birds as a source of food. Beside the development of most efficient drug, a strategy to rapidly diagnose SARS-CoV-2 in suspected patient is also required. The signs and symptoms of SARS-CoV-2 induced COVID-19 are a bit similar to influenza and seasonal allergies (pollen allergies). Person suffering from influenza or seasonal allergy may also exhibit temprature which can be detected by thermo-scanners, hence the person will become suspected. Therefore, an accurate and rapid diagnostic kit or meter for detection of SARS-CoV-2 in suspected patients is required, as the PCR based testing is expensive and time consuming. Different teams of Chinese doctors should immediately sent to Eurpean and other countries, especially spain and Italy to control the over spread of COVID-19, because Chinese doctors have efficiently controlled the outbreak in china and limited the mortality rate to less than 3% only. The therapeutic strategies used by Chinese, should also be followed by other countries.

Acknowledgments

The authors acknowledge the Postdoctoral grant from The Second Affiliated Hospital of Zhengzhou University (for S.K).

Declaration of Competing Interest

The authors of this manuscript declare no conflict of interest.

Biographies

Muhammad Adnan Shereen is a PhD researcher at Wuhan University, working on Zika virus and coronavirus in the aspects of pathogenesis, drug screening and molecular mechanisms. He is an author in 8 articles published in journals with impact factor more than 5 including the recently accepted paper in Nature microbiology.

Suliman Khan has completed his PhD degree from Chinese Academy of Sciences and currently working at second affiliated hospital of Zhengzhou university as postdoctoral scientist. He has published more than 25 articles and 5 on SARS-CoV-2 in well reputed journals including Clinical microbiology and infection (CMI) and Journal of clinical microbiology (ASM-JCM) as first and corresponding author.

Abeer Kazmi is a PhD student at Wuhan University.

Nadia Bashir is a PhD student at Wuhan University working on coronaviruses. She is an author in more than 5 papers published or accepted in renowned journals.

Rabeea Siddique is a PhD student at Zhengzhou university. She has published more than 10 papers in well reputed journals as first or coauthor.

Peer review under responsibility of Cairo University.

A lab technician begins semi-automated testing for COVID-19 at Northwell Health Labs on March 11, 2020, in Lake Success, New York. An emergency use authorization by the FDA allows Northwell to move from manual testing to semi-automated.

• CORONAVIRUS COVERAGE

What is the coronavirus?

COVID-19, the disease caused by the novel coronavirus, has infected tens of thousands of people worldwide. Here’s what you need to know.

Much is left to learn about the coronavirus that is changing life as we know it, but our journey has already yielded many lessons. In late December 2019, reports emerged of a novel coronavirus outbreak connected with pneumonia cases at a wildlife market in Wuhan, China. COVID-19 spread across the nation within weeks—and then stormed its way across the world. By March 11, the World Health Organization labeled COVID-19 a pandemic.

In the time since, we’ve learned some important basics about SARS-CoV-2, the novel coronavirus behind COVID-19—including how it spreads then invades the body and which parts of the world are currently facing serious outbreaks. Here are maps that illustrate its spread and answers to other key questions about COVID-19.

How many cases are there worldwide?

The coronavirus pandemic is reshaping the world. Here’s a closer look at the case counts and fatalities across the world.

Where are cases growing and declining in the U.S.?

The coronavirus is affecting U.S. regions in different ways. Here are the areas where cases and deaths are either decreasing or increasing the most, based on the last seven days compared to the previous week.

What is a coronavirus?

Coronaviruses are a large family of viruses, but only seven of its members infect humans. Four types cause minor illnesses like the common cold, while other coronaviruses have triggered far more devastating impacts such as SARS, MERS, and now COVID-19. Coronaviruses can be zoonotic, meaning they jump from animals to humans.

Like its relatives, COVID-19 is primarily a respiratory disease that starts in the lungs, causing pneumonia-like symptoms, but can also cast a storm across the entire body.

How does COVID-19 spread?

Like other respiratory diseases, COVID-19 primarily spreads through small droplets—saliva or mucus—that an infected person expels when they cough, sneeze, or talk. These droplets can travel three to six feet and remain infectious for anywhere from four to 48 hours, depending on the surface. (The virus may also spread via accidental consumption of fecal matter or aerosols, tiny particles that are mostly a concern in clinical settings.)

You can protect yourself from catching the virus by staying six feet away from others and washing your hands with soap and water for more than 20 seconds.

How long does it last on surfaces?

The virus lives longer on surfaces. Disinfectants that are at least 60 percent alcohol by volume can also kill the virus on plastic and stainless steel surfaces.

What does the coronavirus look like?

Coronaviruses get their name from their spiky structure. Like other coronaviruses , SARS-CoV-2 is spherical with spike proteins that look a bit like a corona, or crown.

How does SARS-CoV-2 invade the body?

Its spiky structure helps the coronavirus latch onto cells that it can invade. Once a virus enters the human body through the eyes, mouth, or nose, it looks for cells with its favorite doorways—proteins called receptors. If the virus finds a compatible receptor, it can invade and start replicating itself. For SARS-CoV-2, that receptor is found in lung cells and the gut.

How does age factor into the severity of the disease?

Currently, children with COVID-19 may be less likely to require intensive care and also have lower fatality rates than adults. The difference in severity is not yet fully understood.

What are the common diagnostic symptoms?

There isn’t a single diagnostic symptom, but some are more common:

What are the chronic conditions that put people at higher risk?

COVID-19 poses a particularly serious threat to people with underlying conditions such as cardiovascular disease, diabetes, chronic lung disease, high blood pressure, and cancer.

How do you diagnose the virus?

Testing is done to diagnose the presence of the virus. Swab samples taken from the nose or mouth are tested for the virus’s genetic material. Researchers are also developing protocols for tests using saliva and blood samples.

When will a vaccine be ready?

To develop immunity, vaccines may contain killed or weakened virus, viral proteins, or viral genetic material. The best strategy to use against SARS-CoV-2 is yet to be determined. It could take until January 2021 —or perhaps much longer —before a vaccine is ready for public use.

See all of National Geographic's coronavirus coverage .

Related Topics

• CORONAVIRUS

You May Also Like

Should you be concerned about bird flu in your milk?

What is 'immune amnesia?' This long-term side effect of measles is newly relevant.

A mysterious new respiratory illness is spreading in dogs. Here’s what we know.

Is long COVID forever? A new study has clues.

Multiple COVID infections can lead to chronic health issues. Here’s what to know.

• Environment
• Paid Content

History & Culture

• History & Culture
• Terms of Use
• Privacy Policy
• Your US State Privacy Rights
• Children's Online Privacy Policy
• Interest-Based Ads
• About Nielsen Measurement
• Do Not Sell or Share My Personal Information
• Nat Geo Home
• Attend a Live Event
• Book a Trip
• Inspire Your Kids
• Shop Nat Geo
• Visit the D.C. Museum
• Learn About Our Impact
• Support Our Mission
• Advertise With Us
• Customer Service
• Renew Subscription
• Manage Your Subscription
• Work at Nat Geo
• Sign Up for Our Newsletters
• Contribute to Protect the Planet

Copyright © 1996-2015 National Geographic Society Copyright © 2015-2024 National Geographic Partners, LLC. All rights reserved

• History Classics
• Your Profile
• Find History on Facebook (Opens in a new window)
• Find History on Twitter (Opens in a new window)
• Find History on YouTube (Opens in a new window)
• Find History on Instagram (Opens in a new window)
• Find History on TikTok (Opens in a new window)
• This Day In History
• History Podcasts
• History Vault

COVID‑19 Pandemic

By: History.com Editors

Updated: March 11, 2024 | Original: April 25, 2023

The outbreak of the infectious respiratory disease known as COVID-19 triggered one of the deadliest pandemics in modern history. COVID-19 claimed nearly 7 million lives worldwide. In the United States, deaths from COVID-19 exceeded 1.1 million, nearly twice the American death toll from the 1918 flu pandemic . The COVID-19 pandemic also took a heavy toll economically, politically and psychologically, revealing deep divisions in the way that Americans viewed the role of government in a public health crisis, particularly vaccine mandates. While the United States downgraded its “national emergency” status over the pandemic on May 11, 2023, the full effects of the COVID-19 pandemic will reverberate for decades.

A New Virus Breaks Out in Wuhan, China

In December 2019, the China office of the World Health Organization (WHO) received news of an isolated outbreak of a pneumonia-like virus in the city of Wuhan. The virus caused high fevers and shortness of breath, and the cases seemed connected to the Huanan Seafood Wholesale Market in Wuhan, which was closed by an emergency order on January 1, 2020.

After testing samples of the unknown virus, the WHO identified it as a novel type of coronavirus similar to the deadly SARS virus that swept through Asia from 2002-2004. The WHO named this new strain SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2). The first Chinese victim of SARS-CoV-2 died on January 11, 2020.

Where, exactly, the novel virus originated has been hotly debated. There are two leading theories. One is that the virus jumped from animals to humans, possibly carried by infected animals sold at the Wuhan market in late 2019. A second theory claims the virus escaped from the Wuhan Institute of Virology, a research lab that was studying coronaviruses. U.S. intelligence agencies maintain that both origin stories are “plausible.”

The First COVID-19 Cases in America

The WHO hoped that the virus outbreak would be contained to Wuhan, but by mid-January 2020, infections were reported in Thailand, Japan and Korea, all from people who had traveled to China.

On January 18, 2020, a 35-year-old man checked into an urgent care center near Seattle, Washington. He had just returned from Wuhan and was experiencing a fever, nausea and vomiting. On January 21, he was identified as the first American infected with SARS-CoV-2.

In reality, dozens of Americans had contracted SARS-CoV-2 weeks earlier, but doctors didn’t think to test for a new type of virus. One of those unknowingly infected patients died on February 6, 2020, but her death wasn’t confirmed as the first American casualty until April 21.

On February 11, 2020, the WHO released a new name for the disease causing the deadly outbreak: Coronavirus Disease 2019 or COVID-19. By mid-March 2020, all 50 U.S. states had reported at least one positive case of COVID-19, and nearly all of the new infections were caused by “community spread,” not by people who contracted the disease while traveling abroad. 

At the same time, COVID-19 had spread to 114 countries worldwide, killing more than 4,000 people and infecting hundreds of thousands more. On March 11, the WHO made it official and declared COVID-19 a pandemic.

The World Shuts Down

Pandemics are expected in a globally interconnected world, so emergency plans were in place. In the United States, health officials at the Centers for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH) set in motion a national response plan developed for flu pandemics.

State by state and city by city, government officials took emergency measures to encourage “ social distancing ,” one of the many new terms that became part of the COVID-19 vocabulary. Travel was restricted. Schools and churches were closed. With the exception of “essential workers,” all offices and businesses were shuttered. By early April 2020, more than 316 million Americans were under a shelter-in-place or stay-at-home order.

With more than 1,000 deaths and nearly 100,000 cases, it was clear by April 2020 that COVID-19 was highly contagious and virulent. What wasn’t clear, even to public health officials, was how individuals could best protect themselves from COVID-19. In the early weeks of the outbreak, the CDC discouraged people from buying face masks, because officials feared a shortage of masks for doctors and hospital workers.

By April 2020, the CDC revised its recommendations, encouraging people to wear masks in public, to socially distance and to wash hands frequently. President Donald Trump undercut the CDC recommendations by emphasizing that masking was voluntary and vowing not to wear a mask himself. This was just the beginning of the political divisions that hobbled the COVID-19 response in America.

When WWI, Pandemic and Slump Ended, Americans Sprang Into the Roaring Twenties

After enduring dark times, Americans were eager for a comeback.

Why the 1918 Flu Pandemic Never Really Ended

After infecting millions of people worldwide, the 1918 flu strain shifted—and then stuck around.

When Mask‑Wearing Rules in the 1918 Pandemic Faced Resistance

Most people complied, but some resisted (or poked holes in their masks to smoke).

Global Financial Markets Collapse

In the early months of the COVID-19 pandemic, with billions of people worldwide out of work, stuck at home, and fretting over shortages of essential items like toilet paper , global financial markets went into a tailspin.

In the United States, share prices on the New York Stock Exchange plummeted so quickly that the exchange had to shut down trading three separate times. The Dow Jones Industrial Average eventually lost 37 percent of its value, and the S&P 500 was down 34 percent.

Business closures and stay-at-home orders gutted the U.S. economy. The unemployment rate skyrocketed, particularly in the service sector (restaurant and other retail workers). By May 2020, the U.S. unemployment rate reached 14.7 percent, the highest jobless rate since the Great Depression . 

All across America, households felt the pinch of lost jobs and lower wages. Food insecurity reached a peak by December 2020 with 30 million American adults—a full 14 percent—reporting that their families didn’t get enough to eat in the past week.

The economic effects of the COVID-19 pandemic, like its health effects, weren’t experienced equally. Black, Hispanic and Native Americans suffered from unemployment and food insecurity at significantly higher rates than white Americans. 

Congress tried to avoid a complete economic collapse by authorizing a series of COVID-19 relief packages in 2020 and 2021, which included direct stimulus checks for all American families.

The Race for a Vaccine

A new vaccine typically takes 10 to 15 years to develop and test, but the world couldn’t wait that long for a COVID-19 vaccine. The U.S. Department of Health and Human Services (HHS) under the Trump administration launched “ Operation Warp Speed ,” a public-private partnership which provided billions of dollars in upfront funding to pharmaceutical companies to rapidly develop vaccines and conduct clinical trials.

The first clinical trial for a COVID-19 vaccine was announced on March 16, 2020, only days after the WHO officially classified COVID-19 as a pandemic. The vaccines developed by Moderna and Pfizer were the first ever to employ messenger RNA, a breakthrough technology. After large-scale clinical trials, both vaccines were found to be greater than 95 percent effective against infection with COVID-19.

A nurse from New York officially became the first American to receive a COVID-19 vaccine on December 14, 2020. Ten days later, more than 1 million vaccines had been administered, starting with healthcare workers and elderly residents of nursing homes. As the months rolled on, vaccine availability was expanded to all American adults, and then to teenagers and all school-age children.

By the end of the pandemic in early 2023, more than 670 million doses of COVID-19 vaccines had been administered in the United States at a rate of 203 doses per 100 people. Approximately 80 percent of the U.S. population received at least one COVID-19 shot, but vaccination rates were markedly lower among Black, Hispanic and Native Americans.

The First ‘Vaccine Passports’ Were Scars from Smallpox Vaccinations

When smallpox ravaged the United States at the turn of the 20th century, many public spaces required people to show their vaccine scars for entry.

When the Supreme Court Ruled a Vaccine Could Be Mandatory

A 1905 decision provided a powerful and controversial precedent for the flexing of government authority.

4 Diseases You’ve Probably Forgotten About Because of Vaccines

Vaccines are so effective at fighting disease that sometimes it’s easy to forget their impact.

COVID-19 Deaths Heaviest Among Elderly and People of Color

In America, the COVID-19 pandemic impacted everyone’s lives, but those who died from the disease were far more likely to be older and people of color.

Of the more than 1.1 million COVID deaths in the United States, 75 percent were individuals who were 65 or older. A full 93 percent of American COVID-19 victims were 50 or older. Throughout the emergence of COVID-19 variants and the vaccine rollouts, older Americans remained the most at-risk for being hospitalized and ultimately dying from the disease.

Black, Hispanic and Native Americans were also at a statistically higher risk of developing life-threatening COVID-19 systems and succumbing to the disease. For example, Black and Hispanic Americans were twice as likely to be hospitalized from COVID-19 than white Americans. The COVID-19 pandemic shined light on the health disparities between racial and ethnic groups driven by systemic racism and lower access to healthcare.

Mental health also worsened during the COVID-19 pandemic. The anxiety of contracting the disease, and the stresses of being unemployed or confined at home, led to unprecedented numbers of Americans reporting feelings of depression and suicidal ideation.

A Time of Social & Political Upheaval

In the United States, the three long years of the COVID-19 pandemic paralleled a time of heightened political contention and social upheaval.

When George Floyd was killed by Minneapolis police on May 25, 2020, it sparked nationwide protests against police brutality and energized the Black Lives Matter movement. Because so many Americans were out of work or home from school due to COVID-19 shutdowns, unprecedented numbers of people from all walks of life took to the streets to demand reforms.

Instead of banding together to slow the spread of the disease, Americans became sharply divided along political lines in their opinions of masking requirements, vaccines and social distancing.

By March 2024, in signs that the pandemic was waning, the CDC issued new guidelines for people who were recovering from COVID-19. The agency said those infected with the virus no longer needed to remain isolated for five days after symptoms. And on March 10, 2024, the Johns Hopkins Coronavirus Resource Center stopped collecting data for its highly referenced COVID-19 dashboard.

Still, an estimated 17 percent of U.S. adults reported having experienced symptoms of long COVID, according to the Household Pulse Survey. The medical community is still working to understand the causes behind long COVID, which can afflict a patient for weeks, months or even years.

HISTORY Vault

Stream thousands of hours of acclaimed series, probing documentaries and captivating specials commercial-free in HISTORY Vault

“CDC Museum COVID Timeline.” Centers for Disease Control and Prevention . “Coronavirus: Timeline.” U.S. Department of Defense . “COVID-19 and Related Vaccine Development and Research.” Mayo Clinic . “COVID-19 Cases and Deaths by Race/Ethnicity: Current Data and Changes Over Time.” Kaiser Family Foundation . “Number of COVID-19 Deaths in the U.S. by Age.” Statista . “The Pandemic Deepened Fault Lines in American Society.” Scientific American . “Tracking the COVID-19 Economy’s Effects on Food, Housing, and Employment Hardships.” Center on Budget and Policy Priorities . “U.S. Confirmed Country’s First Case of COVID-19 3 Years Ago.” CNN .

Sign up for Inside History

Get HISTORY’s most fascinating stories delivered to your inbox three times a week.

By submitting your information, you agree to receive emails from HISTORY and A+E Networks. You can opt out at any time. You must be 16 years or older and a resident of the United States.

More details : Privacy Notice | Terms of Use | Contact Us

I Thought We’d Learned Nothing From the Pandemic. I Wasn’t Seeing the Full Picture

M y first home had a back door that opened to a concrete patio with a giant crack down the middle. When my sister and I played, I made sure to stay on the same side of the divide as her, just in case. The 1988 film The Land Before Time was one of the first movies I ever saw, and the image of the earth splintering into pieces planted its roots in my brain. I believed that, even in my own backyard, I could easily become the tiny Triceratops separated from her family, on the other side of the chasm, as everything crumbled into chaos.

Some 30 years later, I marvel at the eerie, unexpected ways that cartoonish nightmare came to life – not just for me and my family, but for all of us. The landscape was already covered in fissures well before COVID-19 made its way across the planet, but the pandemic applied pressure, and the cracks broke wide open, separating us from each other physically and ideologically. Under the weight of the crisis, we scattered and landed on such different patches of earth we could barely see each other’s faces, even when we squinted. We disagreed viciously with each other, about how to respond, but also about what was true.

Recently, someone asked me if we’ve learned anything from the pandemic, and my first thought was a flat no. Nothing. There was a time when I thought it would be the very thing to draw us together and catapult us – as a capital “S” Society – into a kinder future. It’s surreal to remember those early days when people rallied together, sewing masks for health care workers during critical shortages and gathering on balconies in cities from Dallas to New York City to clap and sing songs like “Yellow Submarine.” It felt like a giant lightning bolt shot across the sky, and for one breath, we all saw something that had been hidden in the dark – the inherent vulnerability in being human or maybe our inescapable connectedness .

More from TIME

Read More: The Family Time the Pandemic Stole

But it turns out, it was just a flash. The goodwill vanished as quickly as it appeared. A couple of years later, people feel lied to, abandoned, and all on their own. I’ve felt my own curiosity shrinking, my willingness to reach out waning , my ability to keep my hands open dwindling. I look out across the landscape and see selfishness and rage, burnt earth and so many dead bodies. Game over. We lost. And if we’ve already lost, why try?

Still, the question kept nagging me. I wondered, am I seeing the full picture? What happens when we focus not on the collective society but at one face, one story at a time? I’m not asking for a bow to minimize the suffering – a pretty flourish to put on top and make the whole thing “worth it.” Yuck. That’s not what we need. But I wondered about deep, quiet growth. The kind we feel in our bodies, relationships, homes, places of work, neighborhoods.

Like a walkie-talkie message sent to my allies on the ground, I posted a call on my Instagram. What do you see? What do you hear? What feels possible? Is there life out here? Sprouting up among the rubble? I heard human voices calling back – reports of life, personal and specific. I heard one story at a time – stories of grief and distrust, fury and disappointment. Also gratitude. Discovery. Determination.

Among the most prevalent were the stories of self-revelation. Almost as if machines were given the chance to live as humans, people described blossoming into fuller selves. They listened to their bodies’ cues, recognized their desires and comforts, tuned into their gut instincts, and honored the intuition they hadn’t realized belonged to them. Alex, a writer and fellow disabled parent, found the freedom to explore a fuller version of herself in the privacy the pandemic provided. “The way I dress, the way I love, and the way I carry myself have both shrunk and expanded,” she shared. “I don’t love myself very well with an audience.” Without the daily ritual of trying to pass as “normal” in public, Tamar, a queer mom in the Netherlands, realized she’s autistic. “I think the pandemic helped me to recognize the mask,” she wrote. “Not that unmasking is easy now. But at least I know it’s there.” In a time of widespread suffering that none of us could solve on our own, many tended to our internal wounds and misalignments, large and small, and found clarity.

Read More: A Tool for Staying Grounded in This Era of Constant Uncertainty

I wonder if this flourishing of self-awareness is at least partially responsible for the life alterations people pursued. The pandemic broke open our personal notions of work and pushed us to reevaluate things like time and money. Lucy, a disabled writer in the U.K., made the hard decision to leave her job as a journalist covering Westminster to write freelance about her beloved disability community. “This work feels important in a way nothing else has ever felt,” she wrote. “I don’t think I’d have realized this was what I should be doing without the pandemic.” And she wasn’t alone – many people changed jobs , moved, learned new skills and hobbies, became politically engaged.

Perhaps more than any other shifts, people described a significant reassessment of their relationships. They set boundaries, said no, had challenging conversations. They also reconnected, fell in love, and learned to trust. Jeanne, a quilter in Indiana, got to know relatives she wouldn’t have connected with if lockdowns hadn’t prompted weekly family Zooms. “We are all over the map as regards to our belief systems,” she emphasized, “but it is possible to love people you don’t see eye to eye with on every issue.” Anna, an anti-violence advocate in Maine, learned she could trust her new marriage: “Life was not a honeymoon. But we still chose to turn to each other with kindness and curiosity.” So many bonds forged and broken, strengthened and strained.

Instead of relying on default relationships or institutional structures, widespread recalibrations allowed for going off script and fortifying smaller communities. Mara from Idyllwild, Calif., described the tangible plan for care enacted in her town. “We started a mutual-aid group at the beginning of the pandemic,” she wrote, “and it grew so quickly before we knew it we were feeding 400 of the 4000 residents.” She didn’t pretend the conditions were ideal. In fact, she expressed immense frustration with our collective response to the pandemic. Even so, the local group rallied and continues to offer assistance to their community with help from donations and volunteers (many of whom were originally on the receiving end of support). “I’ve learned that people thrive when they feel their connection to others,” she wrote. Clare, a teacher from the U.K., voiced similar conviction as she described a giant scarf she’s woven out of ribbons, each representing a single person. The scarf is “a collection of stories, moments and wisdom we are sharing with each other,” she wrote. It now stretches well over 1,000 feet.

A few hours into reading the comments, I lay back on my bed, phone held against my chest. The room was quiet, but my internal world was lighting up with firefly flickers. What felt different? Surely part of it was receiving personal accounts of deep-rooted growth. And also, there was something to the mere act of asking and listening. Maybe it connected me to humans before battle cries. Maybe it was the chance to be in conversation with others who were also trying to understand – what is happening to us? Underneath it all, an undeniable thread remained; I saw people peering into the mess and narrating their findings onto the shared frequency. Every comment was like a flare into the sky. I’m here! And if the sky is full of flares, we aren’t alone.

I recognized my own pandemic discoveries – some minor, others massive. Like washing off thick eyeliner and mascara every night is more effort than it’s worth; I can transform the mundane into the magical with a bedsheet, a movie projector, and twinkle lights; my paralyzed body can mother an infant in ways I’d never seen modeled for me. I remembered disappointing, bewildering conversations within my own family of origin and our imperfect attempts to remain close while also seeing things so differently. I realized that every time I get the weekly invite to my virtual “Find the Mumsies” call, with a tiny group of moms living hundreds of miles apart, I’m being welcomed into a pocket of unexpected community. Even though we’ve never been in one room all together, I’ve felt an uncommon kind of solace in their now-familiar faces.

Hope is a slippery thing. I desperately want to hold onto it, but everywhere I look there are real, weighty reasons to despair. The pandemic marks a stretch on the timeline that tangles with a teetering democracy, a deteriorating planet , the loss of human rights that once felt unshakable . When the world is falling apart Land Before Time style, it can feel trite, sniffing out the beauty – useless, firing off flares to anyone looking for signs of life. But, while I’m under no delusions that if we just keep trudging forward we’ll find our own oasis of waterfalls and grassy meadows glistening in the sunshine beneath a heavenly chorus, I wonder if trivializing small acts of beauty, connection, and hope actually cuts us off from resources essential to our survival. The group of abandoned dinosaurs were keeping each other alive and making each other laugh well before they made it to their fantasy ending.

Read More: How Ice Cream Became My Own Personal Act of Resistance

After the monarch butterfly went on the endangered-species list, my friend and fellow writer Hannah Soyer sent me wildflower seeds to plant in my yard. A simple act of big hope – that I will actually plant them, that they will grow, that a monarch butterfly will receive nourishment from whatever blossoms are able to push their way through the dirt. There are so many ways that could fail. But maybe the outcome wasn’t exactly the point. Maybe hope is the dogged insistence – the stubborn defiance – to continue cultivating moments of beauty regardless. There is value in the planting apart from the harvest.

I can’t point out a single collective lesson from the pandemic. It’s hard to see any great “we.” Still, I see the faces in my moms’ group, making pancakes for their kids and popping on between strings of meetings while we try to figure out how to raise these small people in this chaotic world. I think of my friends on Instagram tending to the selves they discovered when no one was watching and the scarf of ribbons stretching the length of more than three football fields. I remember my family of three, holding hands on the way up the ramp to the library. These bits of growth and rings of support might not be loud or right on the surface, but that’s not the same thing as nothing. If we only cared about the bottom-line defeats or sweeping successes of the big picture, we’d never plant flowers at all.

More Must-Reads from TIME

• The 100 Most Influential People in AI 2024
• Inside the Rise of Bitcoin-Powered Pools and Bathhouses
• How Nayib Bukele’s ‘Iron Fist’ Has Transformed El Salvador
• What Makes a Friendship Last Forever?
• Long COVID Looks Different in Kids
• Your Questions About Early Voting , Answered
• Column: Your Cynicism Isn’t Helping Anybody
• The 32 Most Anticipated Books of Fall 2024

Contact us at [email protected]

• Patient Care & Health Information
• Diseases & Conditions
• Coronavirus disease 2019 (COVID-19)

COVID-19, also called coronavirus disease 2019, is an illness caused by a virus. The virus is called severe acute respiratory syndrome coronavirus 2, or more commonly, SARS-CoV-2. It started spreading at the end of 2019 and became a pandemic disease in 2020.

• Coronavirus

Coronaviruses are a family of viruses. These viruses cause illnesses such as the common cold, severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and coronavirus disease 2019 (COVID-19).

The virus that causes COVID-19 spreads most commonly through the air in tiny droplets of fluid between people in close contact. Many people with COVID-19 have no symptoms or mild illness. But for older adults and people with certain medical conditions, COVID-19 can lead to the need for care in the hospital or death.

Staying up to date on your COVID-19 vaccine helps prevent serious illness, the need for hospital care due to COVID-19 and death from COVID-19 . Other ways that may help prevent the spread of this coronavirus includes good indoor air flow, physical distancing, wearing a mask in the right setting and good hygiene.

Medicine can limit the seriousness of the viral infection. Most people recover without long-term effects, but some people have symptoms that continue for months.

Typical COVID-19 symptoms often show up 2 to 14 days after contact with the virus.

Symptoms can include:

• Shortness of breath.
• Loss of taste or smell.
• Extreme tiredness, called fatigue.
• Digestive symptoms such as upset stomach, vomiting or loose stools, called diarrhea.
• Pain, such as headaches and body or muscle aches.
• Fever or chills.
• Cold-like symptoms such as congestion, runny nose or sore throat.

People may only have a few symptoms or none. People who have no symptoms but test positive for COVID-19 are called asymptomatic. For example, many children who test positive don't have symptoms of COVID-19 illness. People who go on to have symptoms are considered presymptomatic. Both groups can still spread COVID-19 to others.

Some people may have symptoms that get worse about 7 to 14 days after symptoms start.

Most people with COVID-19 have mild to moderate symptoms. But COVID-19 can cause serious medical complications and lead to death. Older adults or people who already have medical conditions are at greater risk of serious illness.

COVID-19 may be a mild, moderate, severe or critical illness.

• In broad terms, mild COVID-19 doesn't affect the ability of the lungs to get oxygen to the body.
• In moderate COVID-19 illness, the lungs also work properly but there are signs that the infection is deep in the lungs.
• Severe COVID-19 means that the lungs don't work correctly, and the person needs oxygen and other medical help in the hospital.
• Critical COVID-19 illness means the lung and breathing system, called the respiratory system, has failed and there is damage throughout the body.

Rarely, people who catch the coronavirus can develop a group of symptoms linked to inflamed organs or tissues. The illness is called multisystem inflammatory syndrome. When children have this illness, it is called multisystem inflammatory syndrome in children, shortened to MIS -C. In adults, the name is MIS -A.

When to see a doctor

Contact a healthcare professional if you test positive for COVID-19 . If you have symptoms and need to test for COVID-19 , or you've been exposed to someone with COVID-19 , a healthcare professional can help.

People who are at high risk of serious illness may get medicine to block the spread of the COVID-19 virus in the body. Or your healthcare team may plan regular checks to monitor your health.

Get emergency help right away for any of these symptoms:

• Can't catch your breath or have problems breathing.
• Skin, lips or nail beds that are pale, gray or blue.
• New confusion.
• Trouble staying awake or waking up.
• Chest pain or pressure that is constant.

This list doesn't include every emergency symptom. If you or a person you're taking care of has symptoms that worry you, get help. Let the healthcare team know about a positive test for COVID-19 or symptoms of the illness.

There is a problem with information submitted for this request. Review/update the information highlighted below and resubmit the form.

From Mayo Clinic to your inbox

Sign up for free and stay up to date on research advancements, health tips, current health topics, and expertise on managing health. Click here for an email preview.

Error Email field is required

Error Include a valid email address

To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and website usage information with other information we have about you. If you are a Mayo Clinic patient, this could include protected health information. If we combine this information with your protected health information, we will treat all of that information as protected health information and will only use or disclose that information as set forth in our notice of privacy practices. You may opt-out of email communications at any time by clicking on the unsubscribe link in the e-mail.

Thank you for subscribing!

You'll soon start receiving the latest Mayo Clinic health information you requested in your inbox.

Sorry something went wrong with your subscription

Please, try again in a couple of minutes

COVID-19 is caused by infection with the severe acute respiratory syndrome coronavirus 2, also called SARS-CoV-2.

The coronavirus spreads mainly from person to person, even from someone who is infected but has no symptoms. When people with COVID-19 cough, sneeze, breathe, sing or talk, their breath may be infected with the COVID-19 virus.

The coronavirus carried by a person's breath can land directly on the face of a nearby person, after a sneeze or cough, for example. The droplets or particles the infected person breathes out could possibly be breathed in by other people if they are close together or in areas with low air flow. And a person may touch a surface that has respiratory droplets and then touch their face with hands that have the coronavirus on them.

It's possible to get COVID-19 more than once.

• Over time, the body's defense against the COVID-19 virus can fade.
• A person may be exposed to so much of the virus that it breaks through their immune defense.
• As a virus infects a group of people, the virus copies itself. During this process, the genetic code can randomly change in each copy. The changes are called mutations. If the coronavirus that causes COVID-19 changes in ways that make previous infections or vaccination less effective at preventing infection, people can get sick again.

The virus that causes COVID-19 can infect some pets. Cats, dogs, hamsters and ferrets have caught this coronavirus and had symptoms. It's rare for a person to get COVID-19 from a pet.

Risk factors

The main risk factors for COVID-19 are:

• If someone you live with has COVID-19 .
• If you spend time in places with poor air flow and a higher number of people when the virus is spreading.
• If you spend more than 30 minutes in close contact with someone who has COVID-19 .

Many factors affect your risk of catching the virus that causes COVID-19 . How long you are in contact, if the space has good air flow and your activities all affect the risk. Also, if you or others wear masks, if someone has COVID-19 symptoms and how close you are affects your risk. Close contact includes sitting and talking next to one another, for example, or sharing a car or bedroom.

It seems to be rare for people to catch the virus that causes COVID-19 from an infected surface. While the virus is shed in waste, called stool, COVID-19 infection from places such as a public bathroom is not common.

Serious COVID-19 illness risk factors

Some people are at a higher risk of serious COVID-19 illness than others. This includes people age 65 and older as well as babies younger than 6 months. Those age groups have the highest risk of needing hospital care for COVID-19 .

Not every risk factor for serious COVID-19 illness is known. People of all ages who have no other medical issues have needed hospital care for COVID-19 .

Known risk factors for serious illness include people who have not gotten a COVID-19 vaccine. Serious illness also is a higher risk for people who have:

• Sickle cell disease or thalassemia.
• Serious heart diseases and possibly high blood pressure.
• Chronic kidney, liver or lung diseases.

People with dementia or Alzheimer's also are at higher risk, as are people with brain and nervous system conditions such as stroke. Smoking increases the risk of serious COVID-19 illness. And people with a body mass index in the overweight category or obese category may have a higher risk as well.

Other medical conditions that may raise the risk of serious illness from COVID-19 include:

• Cancer or a history of cancer.
• Type 1 or type 2 diabetes.
• Weakened immune system from solid organ transplants or bone marrow transplants, some medicines, or HIV .

This list is not complete. Factors linked to a health issue may raise the risk of serious COVID-19 illness too. Examples are a medical condition where people live in a group home, or lack of access to medical care. Also, people with more than one health issue, or people of older age who also have health issues have a higher chance of severe illness.

Related information

• COVID-19: Who's at higher risk of serious symptoms? - Related information COVID-19: Who's at higher risk of serious symptoms?

Complications

Complications of COVID-19 include long-term loss of taste and smell, skin rashes, and sores. The illness can cause trouble breathing or pneumonia. Medical issues a person already manages may get worse.

Complications of severe COVID-19 illness can include:

• Acute respiratory distress syndrome, when the body's organs do not get enough oxygen.
• Shock caused by the infection or heart problems.
• Overreaction of the immune system, called the inflammatory response.
• Blood clots.
• Kidney injury.

Post-COVID-19 syndrome

After a COVID-19 infection, some people report that symptoms continue for months, or they develop new symptoms. This syndrome has often been called long COVID, or post- COVID-19 . You might hear it called long haul COVID-19 , post-COVID conditions or PASC. That's short for post-acute sequelae of SARS -CoV-2.

Other infections, such as the flu and polio, can lead to long-term illness. But the virus that causes COVID-19 has only been studied since it began to spread in 2019. So, research into the specific effects of long-term COVID-19 symptoms continues.

Researchers do think that post- COVID-19 syndrome can happen after an illness of any severity.

Getting a COVID-19 vaccine may help prevent post- COVID-19 syndrome.

The Centers for Disease Control and Prevention (CDC) recommends a COVID-19 vaccine for everyone age 6 months and older. The COVID-19 vaccine can lower the risk of death or serious illness caused by COVID-19.

The COVID-19 vaccines available in the United States are:

2023-2024 Pfizer-BioNTech COVID-19 vaccine. This vaccine is available for people age 6 months and older.

Among people with a typical immune system:

• Children age 6 months up to age 4 years are up to date after three doses of a Pfizer-BioNTech COVID-19 vaccine.
• People age 5 and older are up to date after one Pfizer-BioNTech COVID-19 vaccine.
• For people who have not had a 2023-2024 COVID-19 vaccination, the CDC recommends getting an additional shot of that updated vaccine.

2023-2024 Moderna COVID-19 vaccine. This vaccine is available for people age 6 months and older.

• Children ages 6 months up to age 4 are up to date if they've had two doses of a Moderna COVID-19 vaccine.
• People age 5 and older are up to date with one Moderna COVID-19 vaccine.

2023-2024 Novavax COVID-19 vaccine. This vaccine is available for people age 12 years and older.

• People age 12 years and older are up to date if they've had two doses of a Novavax COVID-19 vaccine.

In general, people age 5 and older with typical immune systems can get any vaccine approved or authorized for their age. They usually don't need to get the same vaccine each time.

Some people should get all their vaccine doses from the same vaccine maker, including:

• Children ages 6 months to 4 years.
• People age 5 years and older with weakened immune systems.
• People age 12 and older who have had one shot of the Novavax vaccine should get the second Novavax shot in the two-dose series.

Talk to your healthcare professional if you have any questions about the vaccines for you or your child. Your healthcare team can help you if:

• The vaccine you or your child got earlier isn't available.
• You don't know which vaccine you or your child received.
• You or your child started a vaccine series but couldn't finish it due to side effects.

People with weakened immune systems

Your healthcare team may suggest added doses of COVID-19 vaccine if you have a moderately or seriously weakened immune system. The FDA has also authorized the monoclonal antibody pemivibart (Pemgarda) to prevent COVID-19 in some people with weakened immune systems.

Control the spread of infection

In addition to vaccination, there are other ways to stop the spread of the virus that causes COVID-19 .

If you are at a higher risk of serious illness, talk to your healthcare professional about how best to protect yourself. Know what to do if you get sick so you can quickly start treatment.

If you feel ill or have COVID-19 , stay home and away from others, including pets, if possible. Avoid sharing household items such as dishes or towels if you're sick.

In general, make it a habit to:

• Test for COVID-19 . If you have symptoms of COVID-19 test for the infection. Or test five days after you came in contact with the virus.
• Help from afar. Avoid close contact with anyone who is sick or has symptoms, if possible.
• Wash your hands. Wash your hands well and often with soap and water for at least 20 seconds. Or use an alcohol-based hand sanitizer with at least 60% alcohol.
• Cover your coughs and sneezes. Cough or sneeze into a tissue or your elbow. Then wash your hands.
• Clean and disinfect high-touch surfaces. For example, clean doorknobs, light switches, electronics and counters regularly.

Try to spread out in crowded public areas, especially in places with poor airflow. This is important if you have a higher risk of serious illness.

The CDC recommends that people wear a mask in indoor public spaces if you're in an area with a high number of people with COVID-19 in the hospital. They suggest wearing the most protective mask possible that you'll wear regularly, that fits well and is comfortable.

• COVID-19 vaccines: Get the facts - Related information COVID-19 vaccines: Get the facts
• Comparing the differences between COVID-19 vaccines - Related information Comparing the differences between COVID-19 vaccines
• Different types of COVID-19 vaccines: How they work - Related information Different types of COVID-19 vaccines: How they work
• Debunking COVID-19 myths - Related information Debunking COVID-19 myths

Travel and COVID-19

Travel brings people together from areas where illnesses may be at higher levels. Masks can help slow the spread of respiratory diseases in general, including COVID-19 . Masks help the most in places with low air flow and where you are in close contact with other people. Also, masks can help if the places you travel to or through have a high level of illness.

Masking is especially important if you or a companion have a high risk of serious illness from COVID-19 .

• Goldman L, et al., eds. COVID-19: Epidemiology, clinical manifestations, diagnosis, community prevention, and prognosis. In: Goldman-Cecil Medicine. 27th ed. Elsevier; 2024. https://www.clinicalkey.com. Accessed Dec. 17, 2023.
• Coronavirus disease 2019 (COVID-19) treatment guidelines. National Institutes of Health. https://www.covid19treatmentguidelines.nih.gov/. Accessed Dec. 18, 2023.
• AskMayoExpert. COVID-19: Testing, symptoms. Mayo Clinic; Nov. 2, 2023.
• Symptoms of COVID-19. Centers for Disease Control and Preventions. https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/symptoms.html. Accessed Dec. 20, 2023.
• AskMayoExpert. COVID-19: Outpatient management. Mayo Clinic; Oct. 10, 2023.
• Morris SB, et al. Case series of multisystem inflammatory syndrome in adults associated with SARS-CoV-2 infection — United Kingdom and United States, March-August 2020. MMWR. Morbidity and Mortality Weekly Report 2020;69:1450. DOI: http://dx.doi.org/10.15585/mmwr.mm6940e1external icon.
• COVID-19 testing: What you need to know. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/testing.html. Accessed Dec. 20, 2023.
• SARS-CoV-2 in animals. American Veterinary Medical Association. https://www.avma.org/resources-tools/one-health/covid-19/sars-cov-2-animals-including-pets. Accessed Jan. 17, 2024.
• Understanding exposure risk. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/your-health/risks-exposure.html. Accessed Jan. 10, 2024.
• People with certain medical conditions. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/people-with-medical-conditions.html. Accessed Jan. 10, 2024.
• Factors that affect your risk of getting very sick from COVID-19. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/your-health/risks-getting-very-sick.html. Accessed Jan. 10, 2024.
• Regan JJ, et al. Use of Updated COVID-19 Vaccines 2023-2024 Formula for Persons Aged ≥6 Months: Recommendations of the Advisory Committee on Immunization Practices—United States, September 2023. MMWR. Morbidity and Mortality Weekly Report 2023; 72:1140–1146. DOI: http://dx.doi.org/10.15585/mmwr.mm7242e1.
• Long COVID or post-COVID conditions. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/long-term-effects/index.html. Accessed Jan. 10, 2024.
• Stay up to date with your vaccines. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/vaccines/stay-up-to-date.html. Accessed Jan. 10, 2024.
• Interim clinical considerations for use of COVID-19 vaccines currently approved or authorized in the United States. Centers for Disease Control and Prevention. https://www.cdc.gov/vaccines/covid-19/clinical-considerations/covid-19-vaccines-us.html#CoV-19-vaccination. Accessed Jan. 10, 2024.
• Use and care of masks. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/about-face-coverings.html. Accessed Jan. 10, 2024.
• How to protect yourself and others. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/prevention.html. Accessed Jan. 10, 2024.
• People who are immunocompromised. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/people-who-are-immunocompromised.html. Accessed Jan. 10, 2024.
• Masking during travel. Centers for Disease Control and Prevention. https://wwwnc.cdc.gov/travel/page/masks. Accessed Jan. 10, 2024.
• AskMayoExpert. COVID-19: Testing. Mayo Clinic. 2023.
• COVID-19 test basics. U.S. Food and Drug Administration. https://www.fda.gov/consumers/consumer-updates/covid-19-test-basics. Accessed Jan. 11, 2024.
• At-home COVID-19 antigen tests — Take steps to reduce your risk of false negative results: FDA safety communication. U.S. Food and Drug Administration. https://www.fda.gov/medical-devices/safety-communications/home-covid-19-antigen-tests-take-steps-reduce-your-risk-false-negative-results-fda-safety. Accessed Jan. 11, 2024.
• Interim clinical considerations for COVID-19 treatment in outpatients. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-care/outpatient-treatment-overview.html. Accessed Jan. 11, 2024.
• Know your treatment options for COVID-19. U.S. Food and Drug Administration. https://www.fda.gov/consumers/consumer-updates/know-your-treatment-options-covid-19. Accessed Jan. 11, 2024.
• AskMayoExpert. COVID:19 Drug regimens and other treatment options. Mayo Clinic. 2023.
• Preventing spread of respiratory viruses when you're sick. Centers for Disease Control and Prevention. https://www.cdc.gov/respiratory-viruses/prevention/precautions-when-sick.html. Accessed March 5, 2024.
• AskMayoExpert. COVID-19: Quarantine and isolation. Mayo Clinic. 2023.
• COVID-19 resource and information guide. National Alliance on Mental Illness. https://www.nami.org/Support-Education/NAMI-HelpLine/COVID-19-Information-and-Resources/COVID-19-Resource-and-Information-Guide. Accessed Jan. 11, 2024.
• COVID-19 overview and infection prevention and control priorities in non-U.S. healthcare settings. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/hcp/non-us-settings/overview/index.html. Accessed Jan. 16, 2024.
• Kim AY, et al. COVID-19: Management in hospitalized adults. https://www.uptodate.com/contents/search. Accessed Jan. 17, 2024.
• O'Horo JC, et al. Outcomes of COVID-19 with the Mayo Clinic Model of Care and Research. Mayo Clinic Proceedings. 2021; doi:10.1016/j.mayocp.2020.12.006.
• At-home OTC COVID-19 diagnostic tests. U.S. Food and Drug Administration. https://www.fda.gov/medical-devices/coronavirus-covid-19-and-medical-devices/home-otc-covid-19-diagnostic-tests. Accessed Jan. 22, 2024.
• Emergency use authorizations for drugs and non-vaccine biological products. U.S. Food and Drug Association. https://www.fda.gov/drugs/emergency-preparedness-drugs/emergency-use-authorizations-drugs-and-non-vaccine-biological-products. Accessed March 25, 2024.
• Coronavirus infection by race
• COVID-19 and pets
• COVID-19 and vitamin D
• COVID-19 and your mental health
• COVID-19 drugs: Are there any that work?
• COVID-19 in babies and children
• COVID-19 travel advice
• COVID-19 vaccines
• COVID-19 vaccines for kids: What you need to know
• COVID-19 variant
• COVID-19 vs. flu: Similarities and differences
• COVID-19, cold, allergies and the flu
• COVID-19: How can I protect myself?
• COVID-19: Who's at higher risk of serious symptoms?
• Debunking coronavirus myths
• Different COVID-19 vaccines
• Fight coronavirus (COVID-19) transmission at home
• Herd immunity and coronavirus
• How do COVID-19 antibody tests differ from diagnostic tests?
• How well do face masks protect against COVID-19?
• Is hydroxychloroquine a treatment for COVID-19?
• Long-term effects of COVID-19
• Mayo Clinic Minute: How dirty are common surfaces?
• Mayo Clinic Minute: You're washing your hands all wrong
• Pregnancy and COVID-19
• Safe outdoor activities during the COVID-19 pandemic
• Safety tips for attending school during COVID-19
• Sex and COVID-19
• Treating COVID-19 at home
• Unusual symptoms of coronavirus

Associated Procedures

• Convalescent plasma therapy
• COVID-19 antibody testing
• COVID-19 tests
• Extracorporeal membrane oxygenation (ECMO)

News from Mayo Clinic

• Mayo Clinic expert discusses updated COVID-19 vaccines Aug. 28, 2024, 03:00 p.m. CDT
• A Mayo Clinic virologist explains FLiRT and why you may need a new COVID-19 vaccination  May 30, 2024, 02:30 p.m. CDT
• Mayo Clinic Q and A: Who should get the latest COVID-19 vaccine? Nov. 21, 2023, 01:30 p.m. CDT
• Can you get COVID-19 and the flu at the same time? A Mayo Clinic expert weighs in Oct. 16, 2023, 04:30 p.m. CDT
• At-home COVID-19 tests: A Mayo Clinic expert answers questions on expiration dates and the new variants Sept. 18, 2023, 04:00 p.m. CDT
• Mayo Clinic expert answers questions about the new COVID-19 vaccine Sept. 13, 2023, 04:15 p.m. CDT
• Study identifies risk factors for long-haul COVID disease in adults Sept. 13, 2023, 02:00 p.m. CDT
• Mayo researchers find vaccine may reduce severity of long-haul COVID symptoms Aug. 23, 2023, 04:34 p.m. CDT
• Corticosteroids lower the likelihood of in-hospital mortality from COVID-19 Aug. 04, 2023, 03:00 p.m. CDT
• COVID-19 vaccine administration simplified April 21, 2023, 07:00 p.m. CDT
• Science Saturday: COVID-19 -- the pandemic that's forever changed laboratory testing April 15, 2023, 11:00 a.m. CDT
• Mayo Clinic expert talks about the new omicron variant April 13, 2023, 02:13 p.m. CDT
• Mayo Clinic to ease universal face mask requirement April 04, 2023, 03:05 p.m. CDT
• 'Deaths of Despair' contribute to 17% rise in Minnesota's death rate during COVID-19 pandemic March 13, 2023, 12:00 p.m. CDT
• Rising cases of COVID-19 variant, XBB.1.5 Jan. 09, 2023, 05:15 p.m. CDT
• Bivalent COVID-19 booster approved for children 6 months and older Dec. 09, 2022, 09:33 p.m. CDT
• Mayo Clinic Minute: How to self-care at home when you have COVID-19 Dec. 06, 2022, 05:00 p.m. CDT
• Halloween safety tips from a Mayo Clinic infectious diseases expert Oct. 27, 2022, 02:00 p.m. CDT
• COVID-19, RSV and flu--season of respiratory infections Oct. 26, 2022, 04:30 p.m. CDT
• COVID-19 bivalent booster vaccines for kids 5-11 approved, Mayo Clinic awaits supply Oct. 13, 2022, 04:54 p.m. CDT
• Questions answered about the COVID-19 bivalent booster vaccines Oct. 12, 2022, 03:30 p.m. CDT
• Will the COVID-19 booster be like an annual flu shot? Sept. 12, 2022, 04:30 p.m. CDT

Products & Services

• A Book: Endemic - A Post-Pandemic Playbook
• A Book: Future Care
• Begin Exploring Women's Health Solutions at Mayo Clinic Store
• Symptoms & causes
• Diagnosis & treatment
• Doctors & departments
• COVID-19 vaccines: Get the facts
• How well do face masks protect against coronavirus?
• Post-COVID Recovery

News on coronavirus disease 2019 (COVID-19)

Learn the latest medical news about COVID-19 on Mayo Clinic News Network.

5X Challenge

Thanks to generous benefactors, your gift today can have 5X the impact to advance AI innovation at Mayo Clinic.

COVID-19: Where we’ve been, where we are, and where we’re going

One of the hardest things to deal with in this type of crisis is being able to go the distance. Moderna CEO Stéphane Bancel

Where we're going

Living with covid-19, people & organizations, sustainable, inclusive growth, related collection.

The Next Normal: Emerging stronger from the coronavirus pandemic

Experts say COVID-19 is endemic. What does that mean?

August 28, 2024 — Since the start of the COVID-19 pandemic, Bill Hanage , associate professor of epidemiology at Harvard T.H. Chan School of Public Health, has been a leading voice in the media, helping the public understand the disease’s evolution. He recently spoke with the New York Times and NPR about the ambivalence characterizing Americans’ attitudes and approaches around COVID during this summer’s surge, and how to understand the disease’s current phase.

The August 27 Times article noted that case numbers are currently high, but hospitalizations and deaths have not reached the levels of previous surges. Masks in public are rare and many people have stopped bothering to test or isolate when they feel ill. As official guidelines and social expectations have shifted, the landscape for navigating one’s own risk can feel trickier.

These shifts reflect what many experts are now saying about COVID: that it has moved from a pandemic to an endemic phase. While epidemiologists’ definitions of endemic can vary, Hanage said in the article, it generally means a constant presence rather than a disruptive outbreak. By that definition, “we’re definitely there” with COVID, he said.

Hanage told the Times that the strict preventive measures seen early in the pandemic were “not just appropriate, but absolutely necessary.” But, he added, “it is just as important to help people onto an off-ramp—to be clear when we are no longer tied to the train tracks, staring at the headlights barreling down.”

But just because COVID is endemic doesn’t mean it’s nothing to worry about anymore, he explained in an August 9 NPR story. “Endemic doesn’t necessarily mean good,” he said. “Tuberculosis is endemic in some parts of the world, and malaria is endemic in some parts of the world. And neither of those are good things.”

Read New York Times article: On the Covid ‘Off-Ramp’: No Tests, Isolation or Masks

Listen to the NPR story: Is COVID endemic yet? Yep, says the CDC. Here’s what that means

Photo: danielvfung / Istock

• All topics »
• Fact sheets

Feature stories

Publications.

• Questions & answers
• Tools and toolkits

Coronavirus disease (COVID-19) pandemic

• Ukraine emergency
• Environment and health

Mpox (monkeypox)

• Calls for experts
• Initiatives
• European Programme of Work
• Sustainable Development Goals
• The Pan-European Mental Health Coalition
• Empowerment through Digital Health
• The European Immunization Agenda 2030
• Healthier behaviours: incorporating behavioural and cultural insights
• Moving towards UHC
• Protecting against health emergencies
• Promoting health and well-being
• News stories
• Media releases

Photo stories

• Questions and answers
• Media Contacts

Newsletters

• European Health Information Gateway
• European health report
• Core health indicators
• WHO Immunization Data portal
• Noncommunicable diseases (NCD) dashboard 
• Events 
• Teams »
• Data and digital health
• Policy & Governance f. Health through the Life Course
• Groups and networks »
• Health Evidence Network (HEN)

The European Health Report 2021 »

• Conflict in Israel and the occupied Palestinian territory
• Armenian refugee health response
• Climate crisis: extreme weather
• Türkiye and Syria earthquakes
• About health emergencies
• Health emergencies newsletter 
• Health emergencies list

• Regional Director
• Executive Council
• Technical centres
• Faces of WHO
• Regional Committee for Europe
• Standing Committee
• Partnerships
• Groups and networks
• WHO collaborating centres

74th session of the WHO Regional Committee for Europe

• Situations /

Links and resources

The coronavirus disease 2019 (COVID-19) pandemic is a global outbreak of coronavirus – an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Cases of novel coronavirus (nCoV) were first detected in China in December 2019, with the virus spreading rapidly to other countries across the world. This led WHO to declare a Public Health Emergency of International Concern (PHEIC) on 30 January 2020 and to characterize the outbreak as a pandemic on 11 March 2020.

On 5 May 2023, more than three years into the pandemic, the WHO Emergency Committee on COVID-19 recommended to the Director-General, who accepted the recommendation, that given the disease was by now well established and ongoing, it no longer fit the definition of a PHEIC. This does not mean the pandemic itself is over, but the global emergency it caused is – for now. A review committee will be established to develop long-term, standing recommendations for countries on how to manage COVID-19 on an ongoing basis.

Since the COVID-19 pandemic started, over 2 million people in the European Region have died from the disease.

On 25 October 2023 WHO/Europe made several changes to its respiratory virus surveillance and data reporting systems. The COVID-19 Situation Dashboard played a pivotal role in providing essential information during the early stages of the pandemic. However, the landscape has now shifted, and so have data needs.

A new WHO/Europe COVID-19 Information Hub is replacing the previous COVID-19 Situation Dashboard to serve as a comprehensive resource, providing links to the most current health information, datasets and products concerning COVID-19.

Within the Hub, WHO/Europe and the European Centre for Disease Prevention and Control (ECDC)’s weekly European Respiratory Virus Surveillance Summary (ERVISS) displays integrated surveillance data for influenza, COVID-19, and respiratory syncytial virus (RSV) in the WHO European Region, including the European Union (EU)/European Economic Area (EEA).

• COVID-19 and related health topics
• Q&As on COVID-19 and related health topics
• Post COVID-19 condition (Long COVID) - fact sheet
• Coronavirus disease (COVID-19) pandemic: global resources
• COVID-19 chatbot: HealthBuddy+
• WHO European Region Operational Updates (archive)
• Global situation dashboard
• Global situation reports
• Surveillance reports (SARS-CoV-2 and mpox in animals)
• Dashboards and interactive platforms
• COVID-19 vaccination
• WHO/Europe COVID-19 vaccination monitor
• Country & Technical Guidance
• Regional publications and guidance on COVID-19
• Global publications and guidance on COVID-19
• Country information
• Public Health and Social Measures in Response to COVID-19
• COVID-19 Health System Response Monitor (HSRM)
• InfluenzaNet
• Emergency Medical Teams - Global EMT
• The Independent Panel for Pandemic Preparedness and Response (IPPR)
• Review Committee on the Functioning of the International Health Regulations (2005) during the COVID-19 Response
• Laboratories

Statement – Solidarity and partnership to save lives: how WHO/Europe worked with the European Union to respond to COVID-19

Amid a summer wave of COVID-19, a new WHO/Europe study confirms the lifesaving impact of vaccines

Half a million children in WHO European Region not fully vaccinated in their first year of life: New 2023 data reveal both gaps and gains in immunization coverage

Essential laboratory equipment arrives in Bulgaria as part of a broader project to protect the health of Ukrainian refugees

Honouring the health humanitarians working to create a safer world

Building trust in vaccination: 350 health workers trained in communication in Kyrgyzstan

Treat mental health as seriously as physical heath: interview with Inês Mália Sarmento, youth activist

Joint bimonthly surveillance report on SARS-CoV-2 and mpox in animals in the European Region, May and...

Strengthened surveillance using a One Health approach in at-risk animal populations and at the animal-human-environment interface is required to timely...

City leadership for age-friendly communities in the post-pandemic era: five lessons for building health...

The COVID-19 pandemic hit older people hardest. This policy brief, intended for planners, policy-makers and politicians, was produced by the 16 cities...

Influenza virus characterization: summary report, Europe, March 2024

Report on the impact of the COVID-19 pandemic on the daily routine and behaviours of school-aged children:...

The WHO Regional Office for Europe established the WHO European Childhood Obesity Surveillance Initiative (‎COSI)‎ in 2007 in response to the need...

A timeline of WHO's COVID-19 Response in the WHO European Region: a living document...

A timeline of WHO’s response to COVID-19 in the WHO European Region: a living document (‎update to version...

This “living” document presents an update to the previous timeline covering from 31 December 2019 to 31 December 20201. It describes the continuation...

A timeline of WHO’s response to COVID-19 in the WHO European Region: a living document (‎Version 2.0...

2020 was a year that will be remembered for generations, for having put the lives and livelihoods of everyone into an unprecedented stress test. Health...

Republic of Moldova - Vaccination saves lives: Supporting the deployment of COVID-19 vaccines and routine vaccination systems in the Eastern Partnership Republic of Moldova - Vaccination saves lives: Supporting the deployment of COVID-19 vaccines and routine vaccination systems in the Eastern Partnership

Belarus - vaccination saves lives: supporting the deployment of covid-19 vaccines and routine vaccination systems in the eastern partnership belarus - vaccination saves lives: supporting the deployment of covid-19 vaccines and routine vaccination systems in the eastern partnership, armenia - vaccination saves lives: supporting the deployment of covid-19 vaccines and routine vaccination systems in the eastern partnership armenia - vaccination saves lives: supporting the deployment of covid-19 vaccines and routine vaccination systems in the eastern partnership.

Increasing Recognition, Research and Rehabilitation for Post COVID-19 Condition (long COVID)

 WHO remains committed to learning more about long COVID and to finding ways to improve the medium- and long-term outcomes for people affected by it, as Dr Hans Henri P. Kluge ...

Taking stock of the health-related SDG during COVID-19

The European Health Report is produced every three years as a flagship publication by the WHO Regional Office for Europe. The aims of the 2021 edition are to provide insight into R ...

Considering physical activity and COVID-19

During the COVID-19 pandemic several public health measures were adopted, including lockdowns and limitations of access to public spaces for physical activity. These measures have ...

Partnering with the European Union to support and strengthen vaccination

The European Union (EU) and WHO/Europe together provide critical assistance to Member States and territories of the WHO European Region on effective vaccination against COVID-19 an ...

Faith Leaders Unite for Health Amid COVID 19

Keeping safe from influenza, COVID 19 and RSV this autumn and winter

From permacrisis to resilience: noncommunicable diseases in emergency preparedness and response

The CO-FLOW long COVID study at Erasmus MC, Rotterdam, Netherlands

Related health topic.

Coronavirus disease (COVID-19)

Coronavirus disease (COVID-19) - Global site

Coronavirus disease (COVID-19) pandemic (Global)

For COVID-19 enquiries contact (7 days a week): WHO/Europe Press Office Tel.: +49 228 815 0432 Email address: [email protected]