Coronaviruses are a type of virus. There are many different kinds, and some cause disease. A coronavirus identified in 2019, SARS-CoV-2, has caused a pandemic of respiratory illness, called COVID-19. What You Need to Know COVID-19 COVID-19 is the disease caused by SARS-CoV-2, the coronavirus that emerged in December 2019. The changes to Covid-19 policies come amid an increase in infections, which city health officials warn could hit 8,000 in the coming weeks. During their.