The current COVID-19 pandemic is caused by an enveloped single-stranded RNA virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It comes from the genus of betacoronaviruses that also includes the two highly pathogenic viruses that caused earlier epidemics of respiratory illness – SARS-CoV and MERS-CoV – as well as two other human coronaviruses (CoV), HCoV-OC43, and HCoV-HKU1.
The current SARS-CoV-2 has an RNA sequence, which is ~80% similar to that of SARS-CoV, and thus many of the antivirals that seem to be active against it were first developed against either the latter or other CoV. One such drug category is the Main Protease inhibitors.
