What Is the Coronavirus (COVID-19)?

Coronaviruses are common causes of colds and respiratory tract infections. At the end of 2019, a new type of coronavirus began making people sick in China. You might hear the virus called COVID-19. Some of the first cases were diagnosed in people who had visited a market selling live seafood and animals.

When viruses spread from animals to people, it can take health experts a while to learn the details of the virus and how it spreads.