A 10-µg dose (third dose) of the Pfizer pediatric booster in healthy children age 5 through 11 generated a 36-fold increase in neutralizing antibody titers compared to levels seen after two doses, according to data from a Phase 2/3 clinical trial.
These data demonstrate an increase in SARS-CoV-2 Omicron variant and wild-type strain neutralizing titers following a Pfizer pediatric booster dose compared to two doses. These data reinforce the potential function of a third dose of the vaccine in maintaining high levels of protection against the virus in this age group.
In the Phase 2/3 clinical trial, data were analyzed from 140 children 5 through 11 years of age received the Pfizer pediatric booster dose approximately 6 months after the second dose of the Pfizer-BioNTech COVID-19 vaccine 10-µg primary series. Data from a sub analysis of 30 sera from this study indicate that serum antibodies induced by a Pfizer pediatric booster dose neutralize the SARS-CoV-2 Omicron variant in this age group, as demonstrated by a 36-fold increase in neutralizing antibody titers compared to levels seen after two doses of the Pfizer-BioNTech COVID-19 Vaccine. A robust response was observed regardless of prior SARS-CoV-2 infection.
Further, immunogenicity data from 140 participants in the Phase 2/3 clinical trial with who had no evidence of prior SARS-CoV-2 infection showed a 6-fold increase (95% CI: 5.0, 7.6) in SARS-CoV-2 wild-type strain–neutralizing geometric mean titers (GMTs) one month after the booster compared to the SARS-CoV-2–neutralizing GMTs one month after the second dose of the Pfizer-BioNTech COVID-19 vaccine, demonstrating a strong immune response in this age group. To date, more than 10,000 children under the age of 12 have participated in clinical trials investigating the Pfizer-BioNTech COVID-19 vaccine, and in this most recent booster data readout (n=401), the vaccine was well tolerated with no new safety signals observed.
Pfizer and BioNTech plan to submit a request for Emergency Use Authorization (EUA) of a pediatric booster dose for children ages 5 through 11 in the U.S. in the coming days. The companies also plan to share these data with the European Medicines Agency (EMA) and other regulatory agencies around the world as soon as possible.
A primary series of two 10-µg doses of the Pfizer-BioNTech COVID-19 Vaccine was previously authorized under EUA for this age group in October 2021. The 10-µg dose level was carefully selected based on safety, tolerability and immunogenicity data.