A booster dose of the Pfizer-BioNTech COVID-19 vaccine elicited a high immune response in children 5 to 11 years of age who completed the primary series, according to data from a phase 2/3 trial.

The Pfizer-BioNTech COVID-19 vaccine is currently authorized for emergency use for active immunization to prevent COVID-19 disease in individuals 5 years of age and older. To assess the safety, tolerability and immunogenicity of a third dose, 140 children 5 to 11 years of age received a 10µg booster dose approximately 6 months after receiving the second dose of the 10µg primary series.

Immunogenicity data from the study showed a 6-fold increase (95% CI, 5.0-7.6) in SARS-CoV-2 wild-type strain-neutralizing geometric mean titers (GMTs) 1 month after the booster compared with GMTs 1 month after the second dose, in children with no evidence of prior SARS-CoV-2 infection.

Data from a subanalysis of 30 human immune sera demonstrated that following a third dose, a 36-fold increase in SARS-CoV-2 Omicron neutralizing antibody titers was observed in this age group. After 3 doses, the 50% neutralizing GMT against Omicron was 993 vs 27 after 2 doses. The neutralizing GMT against the wild-type virus was 2153 (after 3 doses), compared with 335 after 2 doses.

Findings also showed that the booster dose was well tolerated. No new safety signals were reported in this most recent data readout.

Based on these positive results, Pfizer and BioNTech plan to submit a request for Emergency Use Authorization with the Food and Drug Administration in the coming days.


Pfizer and BioNTech announce data demonstrating high immune response following a booster dose of their COVID-19 vaccine in children 5 through 11 years of age. News release. April 14, 2022. https://www.businesswire.com/news/home/20220413006077/en/Pfizer-and-BioNTech-Announce-Data-Demonstrating-High-Immune-Response-Following-a-Booster-Dose-of-their-COVID-19-Vaccine-in-Children-5-Through-11-Years-of-Age