Fig. 1. Regulation of host immune system responses by 2′-O-methyl (2′OMe) modification of SARS‐CoV‐2 RNA.

SARS-CoV-2 RNA replicate in the cytoplasm of infected host cells and encode their own viral 2′-O-methyltransferase (2′-O-MTase), which catalyze the formation of 2′OMe at the 5′-end of SARS-CoV-2 RNA to impede degradation by 5′ exoribonucleases. 2′OMe modification of SARS-CoV2 RNA promotes uncontrolled replication, efficient translation, and evade recognition by the host cell innate immune system via inhibition of interferons production by immune system cells. Importantly, recent study reported that the food and drug administration (FDA) approved drugs include antivirals, alkaloids, cardiac glycosides, anticancer, and steroids act as specific inhibitor for 2′-O-MTase of SARS-CoV-2.