Description
Coronaviruses are a class of RNA viruses widely found in birds and mammals, including humans. Seven coronaviruses are known to cause human infection. The four common types (HCoV-229E, HCoV-OC43, HCoV-NL63 and HCoV-KHKU1) cause common cold symptoms. Two are zoonotic coronaviruses implicated in the severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) outbreaks in 2003 and 2012, respectively. COVID-19 is the pneumonia disease caused by SARS-CoV-2, which is highly infectious. Both SARS-CoV-2 and SARS-CoV originated from coronaviruses in bats and were transmitted to humans through intermediate hosts. SARS-CoV-2 and SARS-CoV are homologous, with their RNA sequences sharing ~80% identity.
