The FDA authorized Pfizer's bivalent vaccine as a booster dose for children aged under 5 years who received 3 doses of monovalent vaccine.
The US Food and Drug Administration (FDA) amended the emergency use authorization (EUA) of the Pfizer-BioNTech bivalent COVID-19 vaccine to provide for a single booster dose of the vaccine in children aged 6 months to 4 years at least 2 months after completion of primary vaccination with 3 doses of the companies’ monovalent COVID-19 vaccine.
The bivalent COVID-19 vaccine includes an mRNA component corresponding to the original SARS-CoV-2 strain to provide broad protection against COVID-19 and targets the Omicron BA.4/BA.5 subvariants, according to the FDA.
“Today’s authorization provides parents and caregivers of children 6 months through 4 years of age who received the three-dose primary series with the monovalent Pfizer-BioNTech COVID-19 Vaccine an opportunity to update their children’s protection by receiving a booster dose with the Pfizer-BioNTech COVID-19 Vaccine, Bivalent,” said Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research, Tuesday in an agency statement. “Currently available data show that vaccination remains the best defense against severe disease, hospitalization and death caused by COVID-19 across all age groups, and we encourage all eligible individuals to make sure that their vaccinations are up to date with a bivalent COVID-19 vaccine.”
Since December 2022, children in this age group who got their first 2 doses with the companies' monovalent vaccine could complete their 3-dose primary series with the bivalent vaccine. At the time, Moderna's bivalent vaccine was authorized as a booster dose as well, for kids aged 6 months to 5 years following a 2-dose primary series.
Children who have received Pfizer's bivalent vaccine as their third dose will not be eligible for a booster dose of a bivalent vaccine at this time "and are expected to have protection against the most serious COVID-19 outcomes," according to the FDA press release.
The FDA’s decision to update the EUA to allow for the fourth dose comes after reviewing immune response data from 60 children aged between 6 months and 4 years who had 3 doses of the monovalent vaccine and a bivalent booster. One month after receiving Pfizer’s bivalent vaccine, the participants "demonstrated an immune response to both the original SARS-CoV-2 virus strain and to Omicron BA.4/BA.5," the agency said in its release.
Additionally, the authorization is supported by the FDA’s previous analyses that evaluated the safety of an original strain/BA.1 booster in adults aged ≥55 years; the monovalent primary series in children aged ≥6 months; monovalent boosters in those aged ≥5 years; and postmarketing safety data with the monovalent COVID-19 vaccine and the bivalent COVID-19 vaccine.
Additional safety data come from 2 clinical studies involving pediatric patients that showed no new safety concerns and no previously unrecognized side effects with a bivalent booster, noted the agency.