COVID-19 is a contagious disease caused by infection with the severe acute respiratory syndrome CoronaVirus2 strain (SARS-CoV-2).

The disease is mainly transmitted via air when people breathe in droplets that infected people release, as they breathe, talk, cough or sneeze. Infected people are more likely to transmit COVID-19 when they are physically close to others however infection can also occur over longer distances. Infectivity begins as early as three days before symptoms appear, and people are most infectious just prior to and during the onset of symptoms. It declines after the first week, but infected people remain contagious for up to 20 days. People can spread the disease even if they are asymptomatic.

The severity of COVID-19 varies. As it is known this virus spreads rapidly and is decidedly transmittable, most people infected with the COVID-19 virus will experience mild to moderate respiratory illness and recover without requiring special treatment. Mild cases typically recover within two weeks, while those with severe or critical diseases may take three to six weeks to recover. In 3–4% of cases (7.4% for those over age 65) symptoms are severe enough to cause hospitalization and those with underlying medical problems like cardiovascular disease, diabetes, chronic respiratory disease, and cancer are more likely to develop serious illness.