The new coronavirus, officially named SARS-CoV-2, can cause a serious disease known as COVID-19. The virus emerged in China in late 2019. As of late August 2020, about six million cases and about 181,000 deaths have been reported in the United States, with about 24 million cases and about 800,000 deaths worldwide.

The coronavirus mainly spreads through the air in respiratory droplets or aerosolized particles released when a person with the virus coughs, talks or breathes. Transmission happens most often indoors. Physical distancing, wearing a face mask and moving activities outdoors are key prevention measures. Click here to learn how to protect yourself and others.

Certain people have a greater risk of acquiring the coronavirus, including 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, 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 “long-haulers” have not regained their previous level of health even months later.

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.


There is currently no approved vaccine for COVID-19, but several candidates have shown promise in early studies. Many experts predicted that a vaccine could become available by early 2021.

Research on treatments for COVID-19 is progressing rapidly. The antiviral drug remdesivir (Veklury) has shown modest benefit in studies, and the steroid dexamethasone was found to reduce the risk of death for severely ill patients. Other treatments, including the malaria drug hydroxychloroquine, have yielded mostly negative results. Be cautious about rumors and overly optimistic information about treatments that have not been tested in randomized clinical trials.

Last Reviewed: August 26, 2020