August 11, 2023August 11, 2023 by Gordon Liu Pfizer’s bivalent COVID-19 vaccine The Pfizer bivalent COVID-19 vaccine targets the original 2020 strain and the Omicron variant BA.1.ATAGI found it triggers a modest improvement in the immune response against both strains.ATAGI advises that the Pfizer bivalent BA.4/5 vaccine can be used as a booster dose by adolescents and adults aged ≥12 years. PrevPreviousFee to Walk-ins