Omicron BA.4 and BA.5: Starting From Scratch Yet Again

(MedPage Today) -- Coronaviruses are single-stranded RNA viruses with large genomes and, until recently, consisted of the mild 229E, OC43, L69, and H53U1 strains, and the "novel" SARS and MERS strains. Sometime in late 2019, a third "novel" coronavirus...