Lower Dose mRNA COVID-19 Vaccine Found Effective in Children

New York-based Pfizer Inc. and BioNTech SE announced today results from a Phase 2/3 trial showing a favorable safety profile and robust neutralizing antibody responses in children 5 to 11 years of age using a two-dose regimen of the Comirnaty vaccine at ten µg administered 21 days apart.

This dosage is smaller than the 30 µg dose used for people 12 and older.

The antibody responses in the participants given ten µg doses were comparable to those recorded in a previous Pfizer-BioNTech study in people 16 to 25 years of age immunized with 30 µg doses.

The data summarized from this Phase 2/3 study, which is enrolling children six months to 11 years of age, was for 2,268participants who were 5 to 11 years of age. In the trial, the SARS-CoV-2–neutralizing antibody geometric mean titer was 1,197.6, demonstrating a strong immune response in this cohort of children one month after the second dose.

This compares well (was non-inferior) to the GMT of 1146.5 from participants ages 16 to 25 years old, who were administered a two-dose regimen of 30 µg.

Further, the mRNA COVID-19 vaccine was well tolerated, with side effects generally comparable to those observed in participants 16 to 25 years of age.

"We are eager to extend the protection afforded by the (Comirnaty) vaccine to this younger population, subject to regulatory authorization...,” stated Albert Bourla, Chairman and CEO, Pfizer, in a press release.

Pfizer and BioNTech confirmed they plan to share these data with the U.S. FDA, European Medicines Agency, and other regulators as soon as possible.

Topline readouts for the other two age cohorts from the trial – children 2-5 years of age and six months to 2 years of age – are expected as soon as the fourth quarter of 2021.

Pfizer and BioNTech plan to submit data from the entire Phase 3 trial for scientific peer-reviewed publication.