On Jun. 17, 2022, Pfizer and BioNTech announced the U.S. Food and Drug Administration (FDA) had granted emergency use authorization (EUA) of the Pfizer-BioNTech COVID-19 Vaccine as a three 3-ﾵg dose series for children 6 months through 4 years of age (also referred to as 6 months to less than 5 years of age). The 3-ﾵg dose was carefully selected as the preferred dose for children under 5 years of age based on safety, tolerability, and immunogenicity data.

The EUA is based on data from a Phase 2/3 randomized, controlled trial that included 4,526 children 6 months through 4 years of age. In the trial, children received the third 3-µg dose at least two months after the second dose at a time when Omicron was the predominant variant. Following a third dose in this age group, the vaccine was found to elicit a strong immune response, with a favorable safety profile similar to placebo.

In the trial, the SARS-CoV-2-neutralizing antibody geometric mean titer (GMT) one month after the third dose was 1,535.2 (95% CI, 1,388.2, 1,697.8) in children 2 through 4 years of age and 1,406.5 (95% CI, 1,211.3, 1,633.1) in infants 6 through 23 months. The antibody responses in both age groups were comparable to those recorded in people 16 to 25 years of age immunized with two 30-µg doses and met the pre-specified success criteria to declare non-inferiority. Demonstration of noninferiority and safety were the regulatory requirements for potential authorization of the Pfizer-BioNTech COVID-19 Vaccine in this age group.