Novel universal anti-rna virus agents

Deuterated and/or methylated N4-hydroxycytidine (NHC) analogs, with deuteration at one or both of the 2'- and 3'-positions on the ribo-sugar moiety and/or methylation of the 3'- positions on the ribo-sugar moiety, pharmaceutical compositions comprising one or more of these compounds, and, optionally, at least one additional therapeutic agent, and methods of treating or preventing infections caused by RNA viruses, curing an infection by an RNA virus, or reducing the biological activity of an RNA virus, are disclosed. Representative RNA viruses include, but are not limited to, Coronaviridae, such as MERSr-CoV, SARS-CoV-1, SARSCoV- 2, HCoV-OC43, HCoV-229E, HCoV-NL63, and HCoV-HKU1, Picornaviridae, Hepeviridae, Noroviruses, Zika, Dengue, Mayaro, Influenza A and B, Parainfluenza, HCV, Rinovirus, tick-borne viruses, Ebola, Lassa, RSV, adenoviruses, enteroviruses, metapneumoviruses, Eastern, Western, and Venezuelan Equine Encephalitis (EEE, WEE and VEE, respectively), and Chikungunya fever (CHIK).