The SARS-CoV-2 coronavirus, which was first identified in China in late 2019, can cause a serious disease known as COVID-19.

The coronavirus mainly spreads through the air in respiratory droplets or aerosolized particles released when a person with the virus coughs, talks or breathes. Most transmission happens indoors. Physical distancing, wearing a face mask and moving activities outdoors are key prevention measures. Some new SARS-CoV-2 variants spread more easily than the original strain and may partially evade immunity. Click here to learn how to protect yourself and others.

Certain people have a greater risk of acquiring the coronavirus, including frontline essential workers and people 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 COVID-19, including older age and preexisting health conditions. Children and young adults can transmit the virus and become seriously ill. Black and Latino communities have both higher infection rates and greater odds of severe illness and death.

The coronavirus can cause a wide range of symptoms. Many people have no apparent symptoms at all (known as asymptomatic) although they can still transmit the virus. Common symptoms include cough, shortness of breath, fever, chills, muscle pain, sore throat and loss of the sense of taste or smell. Click here for information about coronavirus testing and COVID-19 diagnosis.

A majority of people who contract SARS-CoV-2 will have mild to moderate illness and recover without treatment, but others will develop severe disease. At first, COVID-19 was thought to be primarily a respiratory illness, but it has become clear that the coronavirus can cause complications throughout the body. It can take weeks or months for symptoms to resolve. Some  people have not regained their previous level of health even months later. Symptoms associated with long COVID include chronic fatigue, brain fog, persistent breathing difficulty.

One COVID-19 vaccine is fully approved in the United States for people ages 16 or older, and has emergency use authorization for those ages 12 to 15. Two others have emergency authorization for people 18 or older. Click here to learn more about vaccine effectiveness and side effects.

Research on treatments for COVID-19 is progressing rapidly. There is currently only one approved antiviral drug. Other options include monoclonal antibodies and steroids. Click here to learn more about COVID-19 treatments. 

Much remains to be learned about SARS-CoV-2 and COVID-19, including the long-term consequences of the disease, whether people who have had the virus become immune and, if so, how long immunity lasts.

Last Reviewed: September 7, 2021