A coronavirus is a kind of common virus that causes an infection in your nose, sinuses, or upper throat.They’re called coronaviruses because under a microscope, they look like a crown.
Most coronaviruses aren’t dangerous. But in early 2020, after a December 2019 outbreak in China, the World Health Organization identified a new type of coronavirus. Officials named this new virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This is the virus that causes COVID-19.
What Is COVID-19?
Coronavirus disease 2019, or COVID-19, is a disease that can cause what doctors call a respiratory tract infection. It can affect your upper respiratory tract (sinuses, nose, and throat) or lower respiratory tract (windpipe and lungs).
The COVID-19 outbreak quickly spread around the world. It spreads the same way other coronaviruses do, mainly through person-to-person contact. Infections range from mild to serious.
COVID-19 is one of seven types of coronavirus, including the ones that cause severe diseases like Middle East respiratory syndrome (MERS) and sudden acute respiratory syndrome (SARS). The other coronaviruses cause most of the colds that affect us during the year but aren’t a serious threat for otherwise healthy people.
Is There More Than One Strain of SARS-CoV-2?
It’s normal for a virus to change, or mutate, as it infects people. A Chinese study of 103 COVID-19 cases suggests the virus that causes it has done just that. They found two strains, which they named L and S. The S type is older, but the L type was more common in early stages of the outbreak. They think one may cause more cases of the disease than the other, but they’re still working on what it all means.