Pfi zer Bivalent Vaccine Booster Dose for Children 6 Months to 4 Years Old

ABSTRACT

Pfizer bivalent COVID-19 vaccine booster dose for children six months to four-years-old is discussed. The FDA has expanded its Emergency Use Authorization (EUA) for the COVID-19 vaccine manufactured by Pfizer/BioNTech (Comirnaty) to permit use of the bivalent formulation (containing mRNA from the original and BA.4/5 Omicron strains of SARS-CoV-2) as a booster dose in children 6 months to 4 years old who completed the primary series with 3 doses of the monovalent formulation more than 2 months previously. Expansion of the EUA was primarily based on the results of an unpublished immunogenicity trial (summarized in the FDA fact sheet) in which 60 children 6 months to 4 years old who had received 3 primary-series doses of the Pfizer monovalent vaccine were given a booster dose of the bivalent vaccine.