What virus causes the disease COVID-19?

SARS-CoV-2 is the virus that causes the disease COVID-19. Its name stands for severe acute respiratory syndrome coronavirus 2, reflecting its relationship to SARS-CoV, the coronavirus responsible for the 2002–2004 SARS outbreak.

SARS-CoV-2 is an enveloped betacoronavirus with spike proteins on its surface. These proteins help the virus attach to and enter certain human cells, including cells in the respiratory tract. After infection, symptoms may include fever, cough, sore throat, fatigue, loss of smell or taste, and breathing difficulty, although some infections cause no noticeable symptoms.

The disease COVID-19 was first identified in late 2019 and led to a global pandemic. The virus has produced genetically distinct variants, including Alpha, Delta, and Omicron. COVID-19 is the illness; SARS-CoV-2 is the infectious agent, a distinction often blurred in casual conversation.

Rhinoviruses commonly cause colds, MERS-CoV causes Middle East respiratory syndrome, and influenza A is a flu virus. None of those is the virus responsible for COVID-19.