Coronavirus disease (COVID-19) is an infectious disease caused by a new virus. Coronaviruses are a large group of viruses that cause diseases in animals and humans. They often circulate among camels, cats, and bats, and can sometimes evolve and infect people.
The viruses can cause mild respiratory infections in humans, such as the common cold, which may lead to severe illnesses, such as pneumonia. There is currently no vaccine to prevent coronavirus disease in 2019 (COVID-19).