Omicron’s Evolution and the New Bivalent COVID-19 Booster

Last month new “bivalent” booster vaccines made by Moderna and Pfizer became available that protect against currently circulating Omicron variants as well as earlier strains of the SARS-CoV-2 virus that causes COVID-19. This Q&A features Joel Ernst, MD, a UCSF professor of medicine whose research aims to understand how pathogens evade the immune system.