The SARS-CoV-2 coronavirus, which was first identified in China in late 2019, can cause a serious disease known as COVID-19. A majority of people who contract the virus will have mild to moderate illness and recover without treatment, but others develop severe disease. At first, COVID was thought to be primarily a respiratory illness, but it has become clear that the virus can cause complications throughout the body. Some people develop long-term symptoms known as long COVID.
SARS-CoV-2 mainly spreads through the air in respiratory droplets or aerosolized particles, especially in crowded indoor settings. Some newer virus variants spread more easily than the original strain and are better at evading immunity from past infection or vaccination. Click here to learn about COVID testing and how to protect yourself and others.
Some people are at greater risk of acquiring the virus, including those who live in crowded households or institutional settings, such as nursing homes or prisons. A different set of risk factors increases the chances of developing severe illness. While older people and those with other health conditions are more likely to develop severe disease, healthy young people—including children—can also become seriously ill. Black and Latino communities have both higher infection rates and greater odds of severe illness and death.
SARS-CoV-2 can cause a wide range of symptoms. Many people have no apparent symptoms at all (known as being asymptomatic), but they can still transmit the virus. Common symptoms include cough, shortness of breath, fever or chills, muscle or joint aches, sore throat, headache, gastrointestinal symptoms and loss of the sense of taste or smell.
Some people develop prolonged symptoms—including severe fatigue, brain fog and inability to exercise—that can last for months or years. The biology of long COVID is not well understood, and there are no approved treatments, but this is an active area of clinical research.
Three COVID vaccines are authorized in the United States, from Pfizer-BioNTech, Moderna and Novavax. The Centers for Disease Control and Prevention (CDC) recommends updated Pfizer-BioNTech or Moderna vaccines for everyone ages 6 months and older. Authorization of the updated Novavax vaccine is pending. Click here for more information about COVID vaccines and current CDC recommendations.
A majority of people with COVID will have mild to moderate illness and recover without treatment, but others will develop severe disease. Three approved antiviral medications can lower the risk of disease progression: nirmatrelvir/ritonavir (Paxlovid), remdesivir (Veklury) and molnupiravir (Lagevrio). Click here to learn more about COVID treatment.
Last Reviewed: September 15, 2023