The FDA has expanded its Emergency Use Authorizations (EUAs) for the COVID-19 vaccines manufactured by Pfizer/BioNTech (Comirnaty) and Moderna (Spikevax) to permit use of the bivalent formulations of these products (containing mRNA from the original and BA.4/5 Omicron strains of SARS-CoV-2) in children as young as 6 months. The bivalent Pfizer vaccine is authorized for use as the final dose of a 3-dose primary series in children 6 months to 4 years old. The bivalent Moderna vaccine is authorized for use as a booster dose in children 6 months to 5 years old who completed a primary series with the monovalent Moderna vaccine.1 Bivalent vaccines had previously been authorized for use as a booster dose in persons ≥5 years old (Pfizer) or ≥6 years old (Moderna).2
CLINICAL STUDIES – No data on use of the bivalent vaccines in young children are available. Expansion of the EUAs was based on the results of efficacy trials of the corresponding monovalent vaccines in these age groups and on immunogenicity and safety trials of bivalent vaccines containing mRNA from the original and BA.1 Omicron strains of SARS-CoV-2 (not authorized in the US) in adults.1,3
RECOMMENDATIONS – CDC guidelines recommend a 3-dose primary series of the Pfizer vaccine for children 6 months to 4 years old. Children should receive two doses of the monovalent formulation given 3-8 weeks apart, followed by a dose of the bivalent formulation given ≥8 weeks after the second monovalent dose.4 The recommended bivalent vaccine dose is 3 mcg/0.2 mL (maroon-capped vials).5 The monovalent Pfizer vaccine is no longer authorized for use as a third primary-series dose in this population. Children who have already completed a three-dose primary series with the monovalent Pfizer vaccine are not currently eligible for booster immunization.1,4
The CDC recommends that children 6 months to 5 years old receive a booster dose of the bivalent Moderna vaccine ≥2 months after completing a primary series with the monovalent Moderna vaccine.4 The booster dose of the bivalent Moderna vaccine in children 6 months to 5 years old is 10 mcg/0.2 mL (yellow-labeled vials).6
- FDA News Release. Coronavirus (COVID-19) update: FDA authorizes updated (bivalent) COVID-19 vaccines for children down to 6 months of age. December 8, 2022. Available at: https://bit.ly/3FmZHcm. Accessed December 13, 2022.
- COVID update: Bivalent vaccine booster doses authorized for children ≥5 years old. Med Lett Drugs Ther 2022 October 17 (epub).
- COVID-19 update: Bivalent Pfizer and Moderna COVID-19 vaccines for booster immunization. Med Lett Drugs Ther 2022; 64:159.
- CDC. Interim clinical considerations for use of COVID-19 vaccines currently approved or authorized in the United States. December 9, 2022. Available at: https://bit.ly/3KgPdxl. Accessed December 13, 2022.
- FDA. Pfizer-BioNTech COVID-19 vaccines. December 8, 2022. Available at: https://bit.ly/3Mz59fj. Accessed December 13, 2022.
- FDA. Moderna COVID-19 vaccines. December 8, 2022. Available at: https://bit.ly/3MwVyWk. Accessed December 13, 2022.