COVID-19, also called coronavirus disease 2019, is an illness caused by a virus. The virus is called severe acute respiratory syndrome coronavirus 2, or more commonly, SARS-CoV-2. It started spreading at the end of 2019 and became a pandemic disease in 2020. The virus that causes COVID-19 spreads most commonly through the air in tiny droplets of fluid between people in close contact. Many people with COVID-19 have no symptoms or mild illness. But for older adults and people with certain medical conditions, COVID-19 can lead to the need for care in the hospital or death. Staying up to date on your COVID-19 vaccine helps prevent serious illness, the need for hospital care due to COVID-19 and death from COVID-19. Other ways that may help prevent the spread of this coronavirus includes good indoor air flow, physical distancing, wearing a mask in the right setting and good hygiene. Medicine can limit the seriousness of the viral infection. Most people recover without long-term effects, but some people have symptoms that continue for months.