Coronaviruses

Coronaviruses are a family of viruses that circulate among animals and humans .   

There are four seasonal coronaviruses that normally infect humans, such as types 229E, NL63, OC43, and HKU11. These coronaviruses typically cause mild to moderate upper-respiratory tract illnesses, similar to the common cold. 

Additionally, other coronaviruses such as SARS-CoV-1 (causing SARS), SARS-CoV-2 (causing COVID-19) and MERS-CoV (causing MERS) can cause disease in humans. They can cause symptoms ranging from ranging from the common cold to severe acute respiratory infection. 

Other coronaviruses are normally transmitted among animals, but some might have the potential to spill over and adapt to humans like it happened with SARS-CoV-2. The exact origin of transmission of SARS-CoV-2 from animals to humans however, is still unknown.