Pfizer seeks USFDA emergency use nod for COVID booster in children aged 5 through 11 years

The Phase 1/2/3 trial initially enrolled up to 4,500 children ages 6 months to under 12 years of age in the United States, Finland, Poland, and Spain from more than 90 clinical trial sites. Additional children have been enrolled in all age groups following study amendments and the trial currently includes more than 10,000 children. The trial was originally designed to evaluate the safety, tolerability, and immunogenicity of the Pfizer-BioNTech COVID-19 Vaccine on a two-dose schedule (approximately 21 days apart) in three age groups: ages 5 to under 12 years; ages 2 to under 5 years; and ages 6 months to under 2 years. Based on the Phase 1 dose-escalation portion of the trial, children ages 5 to under 12 years received a two-dose schedule of 10-µg each while children under age 5 received a lower 3-µg dose for each injection in the Phase 2/3 study. The trial enrolled children with or without prior evidence of SARS-CoV-2 infection. In December 2021, Pfizer and BioNTech announced the companies would test a third 3-µg dose given at least two months after the second dose in children under age 5 and a third dose of the 10-µg formulation in children 5 to under 12 years of age.