In addition to an extremely pathogenic strains of CoV; MERS-CoV, SARS-CoV and SARS-CoV-2, belonging to same genus (b-coronavirus), four other low-pathogenic endemic strains in humans are also reported: HCoV-229E, HCoVHKU1, HCoV-NL63 and HCoV-OC43.Till date, no vaccines or therapeutics are available against any human infecting strain of CoVs.