SARS-CoV-2(18) inhibitor(14) COVID-19 pandemic(13) protease(11) M pro(11) inhibitors(11) Analysis(9) COVID-19(9) variants(8) drug target(8) Antiviral agents(7) effort(7) antiviral agent(7) death(6) Compound(6) molecular(6) in vitro(6) Infection(6) SARS-CoV-2.(6) variant(6) structures(5) Antiviral(5) main protease(5) demonstrated(4) HCV(4) wildtype(4) public health threat(4) 3CL(pro)(4) prevalent(4) Mutation(4)