COVID-19 General Information


Coronavirus disease 2019 (COVID-19) is characterized by severe acute respiratory syndrome, (SARS) which is a contagious and sometimes fatal respiratory illness. COVID-19 is caused by a coronavirus that is similar to the one that caused the SARS outbreak in 2003. Because of these characteristics, this coronavirus is formally known as “SARS-CoV-2.” The number “19” is associated with COVID-19 because the first documented case of someone being infected with SARS-CoV-2 occurred in December 2019. On March 11, 2020, the World Health Organization (WHO) classified the COVID-19 outbreak as a global pandemic, recognizing that the virus had spread worldwide. The coronavirus pandemic is the first pandemic in history to be caused by a coronavirus, as opposed to other types of infectious pathogens.


If a person is exposed to the coronavirus, they may experience a wide range of symptoms, they may not experience any symptoms at all, or they may begin experiencing symptoms several days after first being exposed. A person exposed to the coronavirus can spread the coronavirus to people near them through airborne respiratory droplets, even if they are not currently experiencing symptoms of COVID-19. Symptoms of being infected by the coronavirus include:

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

While the symptoms of COVID-19 vary greatly between people who are exposed to the coronavirus, the condition can be fatal. Mortality is increased in people of advanced age and those with certain underlying conditions, including cardiovascular disease, chronic respiratory disease, diabetes, chronic kidney disease, obesity, and cancer, as well as people with compromised immune systems.

Some people who recover from COVID-19 continue to experience chronic symptoms, which is a distinct condition referred to as “long COVID.” Review our Long COVID General Information page to learn more.

If a patient recovers from COVID-19 and does not experience persistent symptoms, they may still be at heightened risk of developing other associated conditions following their recovery. Review our Post-COVID Conditions page to learn more.

Depending on the severity of a person’s COVID-19 symptoms, they may qualify for disability benefits, such as short-term disability insurance, long-term disability insurance, and Social Security Disability Insurance (SSDI), among others. Review our COVID-19 and Disability Benefits page to learn more.


Because of how easily the coronavirus can spread between people, the best strategies for avoiding exposure to the coronavirus include wearing a face mask, maintaining several feet of distance from other people (“social distancing”), and washing your hands frequently. Several vaccines that protect against the coronavirus have been developed. The U.S. Food and Drug Administration (FDA) has granted these COVID-19 vaccines Emergency Use Authorization (EUA) for use in certain populations and has granted full approval for the use of three vaccines in certain populations (Comirnaty and Spikevax). These vaccines are available to the American public for free. These vaccines are highly effective at protecting adults from developing severe symptoms of COVID-19 and significantly reducing the mortality of the disease. However, while the COVID-19 vaccines can protect against severe COVID-19 symptoms and death, they do not completely prevent the virus from spreading. They also do not eliminate the risk of developing long COVID following COVID-19 infection. While imperfect, the benefits of getting vaccinated against COVID-19 likely outweigh the risks associated with the vaccine itself and the health consequences of contracting COVID-19 for most people.

On August 31, 2022, the FDA authorized the use of bivalent mRNA COVID-19 vaccine boosters. Bivalent vaccines contain updated components that provide protection against both the original strain of the coronavirus and the omicron variant. Following this authorization, the original, outdated formulation of the mRNA COVID-19 vaccines will no longer be available for vaccine boosters. Newer vaccines, known as “pan-coronavirus vaccines,” are being developed that can protect against all future coronavirus variants.

To learn more about the eligibility criteria for the COVID-19 vaccines, please review our Vaccine Eligibility Guide.

The COVID-19 vaccines may not be effective at preventing severe COVID-19 infection for individuals with compromised immune systems because they are unable to mount an adequate immune response to the vaccine. Additionally, some individuals may be unable to get vaccinated because they have a history of severe adverse reactions to components of the vaccine. Individuals belonging to either of these groups may be able to utilize a monoclonal antibody treatment for pre-exposure prophylaxis (PrEP) to acquire temporary protection against COVID-19. 

  • Evusheld (tixagevimab plus cilgavimab) is a monoclonal antibody treatment that is administered as one intramuscular injection every six months to provide temporary protection against COVID-19.
    • The FDA has granted EUA for the use of Evusheld in adults and young adults 12 years of age and older who are not currently infected with COVID-19 and have not recently been exposed to the virus. Evusheld is only authorized for individuals who have moderate-to-severe immunocompromise due to a medical condition or immunosuppressive treatments and individuals who are unable to get vaccinated against COVID-19 because they have a history of severe adverse reactions to components of the vaccine.
    • Monoclonal antibody treatments are not a substitute for vaccination.
    • Evusheld may not be effective at protecting against newer variants of COVID-19.


Currently, there is no cure for COVID-19. However, some strategies may be employed to reduce disease severity. The U.S. Centers for Disease Control and Prevention (CDC) recommends staying home, drinking plenty of fluids, and isolating yourself away from other people in your home to prevent spreading the coronavirus to them. Additionally, the CDC recommends resting while monitoring your symptoms and taking over-the-counter medications like acetaminophen or ibuprofen to reduce fever. If symptoms become more severe, contact your health care provider immediately. Severe symptoms of COVID-19 that present a medical emergency include:

  • Trouble breathing
  • Persistent pain or pressure in the chest
  • New confusion
  • Inability to wake or stay awake
  • Pale, gray, or blue-colored skin, lips, or nail beds, depending on skin tone

If your symptoms are severe enough to require additional medical care or if you become hospitalized due to COVID-19, your treating health care provider may recommend treatment to reduce the severity of your symptoms. The FDA has approved or granted EUA for the following treatments, which can reduce the severity of COVID-19 symptoms and reduce disease mortality:

  • Paxlovid (ritonavir-boosted nirmatrelvir) is an oral antiviral medication that is available to high-risk patients. Paxlovid is a pill that is taken twice per day for five consecutive days. For this treatment to be effective, it must be initiated as soon as possible after symptoms first appear. Paxlovid has significant drug interactions, which requires a patient’s treating health care provider to conduct a comprehensive evaluation of their current medications to identify potentially dangerous drug-drug interactions before prescribing Paxlovid. The COVID-19 treatment guidelines contain a list of medications that are known to interact with Paxlovid.
    • The FDA has granted EUA for the use of Paxlovid in non-hospitalized adult and pediatric patients over the age of 12 who have mild-to-moderate COVID-19 and who are at high risk of disease progression.
    • In limited situations, pharmacists are authorized to prescribe Paxlovid directly to patients.
  • Lagevrio (molnupiravir) is an oral antiviral medication that is available to high-risk patients. Lagevrio is a pill that is taken twice per day for five consecutive days. For this treatment to be effective, it must be initiated as soon as possible after symptoms first appear. The FDA has limited the availability of this treatment due to concerns that it has the potential to cause DNA mutations. However, the FDA has concluded that Lagevrio has a low risk of causing such mutations.
    • The FDA has granted EUA for the use of Lagevrio in non-hospitalized adult patients who have mild-to-moderate COVID-19, who are at high risk of disease progression, and who do not have access to alternative antiviral treatments because they are unavailable or clinically inappropriate. 
  • Veklury (remdesivir) is an antiviral treatment that is administered by intravenous infusion or injection at a hospital or infusion center. For this treatment to be effective, it must be administered within seven days of symptoms first appearing.
    • The FDA has approved Veklury for the treatment of non-hospitalized patients with mild-to-moderate COVID-19 and for hospitalized patients.
    • The FDA has granted EUA for the use of Veklury in certain non-hospitalized and hospitalized pediatric COVID-19 patients.
  • Monoclonal antibodies (anti-SARS-CoV-2 mAbs) are antibody treatments that are produced in a laboratory and administered by intravenous infusion at a hospital or infusion center. Monoclonal antibody treatments work by restoring, enhancing, or imitating the body’s natural immune response against viral pathogens. For this treatment to be effective, it must be administered within seven days of symptoms first appearing. The effectiveness of monoclonal antibody treatments fluctuates depending on the COVID-19 variant they are used against. The FDA has historically amended the availability of these treatments to ensure that the available monoclonal antibody treatments are effective against the strains of COVID-19 that are currently circulating.
    • The FDA has granted EUA for the use of monoclonal antibodies in non-hospitalized adult patients who have mild-to-moderate COVID-19 and who are at high risk of progressing to severe disease.
    • Monoclonal antibody treatments are not a substitute for vaccination.
    • Monoclonal antibodies can be effective for reducing disease severity in patients with severely compromised immune systems. However, this treatment approach could result in viral mutations that are resistant to treatment. Additional research is needed to assess this risk.
  • Convalescent plasma is an antibody treatment that is made from the blood plasma of patients who have successfully recovered from COVID-19. When administered to patients with active COVID-19, the antibodies in convalescent plasma can help suppress the viral infection.
    • The FDA has granted EUA for the use of Convalescent plasma in hospitalized COVID-19 patients who are immunosuppressed or who are receiving immunosuppressive treatment.
  • Corticosteroids, such as dexamethasone, are anti-inflammatory medications that are prescribed to treat a variety of conditions. Corticosteroids may improve clinical outcomes and reduce disease severity for hospitalized COVID-19 patients who require supplemental oxygen. Corticosteroids accomplish this by reducing systemic inflammation that can lead to lung injury and multi-system organ dysfunction.
    • There is insufficient evidence to support the use of inhaled corticosteroids for the treatment of COVID-19.

The National Institutes of Health (NIH) has published treatment guidelines for patients with COVID-19. These guidelines include up-to-date information on a variety of treatment options, including experimental therapies that have not yet been approved for the treatment of COVID-19. The New York Times also maintains a treatment tracker that lists the available treatments for COVID-19.


When a person becomes infected with COVID-19, the virus replicates within that person’s body.  This causes new copies of the virus to inherit genetic mutations that differentiate it from the original virus, which have the potential to disrupt the human immune system’s ability to respond to the coronavirus. When a genetic mutation results in a more infectious variant of the coronavirus, that variant often spreads to other people and particularly infectious variants can spread so quickly that they represent a majority of new infections.

The CDC has begun classifying variants of COVID-19 found in the United States into three separate categories: Variants of Interest, Variants of Concern, and Variants of High Consequence. These classifications are informed by characteristics of each variant, such as their ability to evade diagnostic testing, their ability to infect people who have been vaccinated, greater transmissibility, increased disease severity and mortality, and resistance to treatment. Currently, there are several Variants of Interest and Variants of Concern, while no Variants of High Consequence have yet been identified. For more information about COVID-19 variants, review the CDC’s Variants and Genomic Surveillance page.

Do you have additional questions about COVID-19? Check out our COVID-19 FAQ page.

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