FDA Authorizes Bivalent COVID-19 Vaccine Booster Dose for Children

On March 14, the FDA approved emergency use authorization (EUA) of the COVID-19 bivalent vaccine as a booster for children between six months and four years.

The Bivalent Pfizer-BioNTech COVID-19 vaccine may be administered to children after at least two months of their initial vaccination with three doses of the monovalent Pfizer-BioNTech COVID-19 vaccine.

The FDA advises parents and caregivers are aware of these points before vaccinating their children:

• Children between the age of six months and four years who received their three-dose primary vaccination with the monovalent Pfizer-BioNTech COVID-19 vaccine at least two months prior are permitted to get their booster shot of the Pfizer-BioNTech COVID-19 Vaccine, Bivalent.
• Beginning in December 2022, children between six months and four years who had the first two doses of the monovalent Pfizer-BioNTech COVID-19 vaccine should continue with their three-dose primary series with the Pfizer-BioNTech COVID-19 Vaccine, Bivalent. This age group is currently not eligible to receive a booster dose of the bivalent vaccine and is presumed to have immunity against fatal COVID-19 consequences. FDA's authorization on March 14 is for those between six months and four years old who already had their three-dose primary vaccination series with the monovalent Pfizer-BioNTech COVID-19 vaccine before the Pfizer-BioNTech COVID-19 vaccine. The bivalent vaccine was approved as a third dose in the three-dose main chain.
• The approved Pfizer-BioNTech COVID-19 Vaccine, Bivalent, contains an mRNA equivalent to the primary virus strain to issue immunity against COVID-19 and an mRNA component parallel to the omicron variant BA.4 and BA.5 line to give a superior shield against the omicron variant.

"Currently available data show that vaccination remains the best defense against severe diseases, 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," says director of the FDA’s Center for Biologics Evaluation and Research Peter Marks, M.D., Ph.D.

FDA's authorization came after testing immunity response from 60 children in the age group who had their primary vaccination with three doses of monovalent Pfizer-BioNTech COVID-19 vaccine on top of a booster dose Pfizer-BioNTech COVID-19 Vaccine, Bivalent in a clinical research study. After a month of receiving the Pfizer-BioNTech COVID-19 Vaccine, Bivalent, children in the study showed immunity to both the original SARS-CoV-2 virus strain and to omicron BA.4/BA.5.

Additionally, FDA's authorization comes after preliminary analyses of primary vaccination efficacy with the monovalent Pfizer-BioNTech COVID-19 vaccine among individuals over 16 and children between six months and four years. They also considered immunity response from those 55 or older who received one booster dose with an investigational Pfizer-BioNTech bivalent COVID-19 vaccine (original and omicron BA.1).

Safety of the vaccine

The FDA's authorization is based on the agency's prior evaluations regarding safety:

• A clinical study was conducted with individuals over the age of 55 that received a booster dose of Pfizer-BioNTech’s investigational bivalent COVID-19 vaccine (original and omicron BA.1.)
• Clinical studies involving individuals over the age of six months with the monovalent Pfizer-BioNTech COVID-19 vaccine.
• Clinical studies among individuals over the age of five who received a booster with monovalent Pfizer-BioNTech COVID-19 Vaccine, which was authorized formerly but is now forbidden.
• Post marketing surveillance data using the monovalent Pfizer-BioNTech COVID-19 Vaccine and Pfizer-BioNTech COVID-19 Vaccine, Bivalent.

Additionally, safety was evaluated in participants in two clinical trials involving those six months of age or older. Participants in one trial were six months to 11 years old. They had already received a three-dose primary series of the monovalent Pfizer-BioNTech COVID-19 vaccine and a bivalent Pfizer-BioNTech COVID-19 vaccine booster.

The most frequent adverse effects among 24 subjects (six months through 23 months) were irritability, sleepiness, injection site redness, soreness, swelling, reduced appetite, tiredness, and temperature. The most frequent adverse effects among 36 subjects, aged two to four years, were tiredness, discomfort at the injection site, redness and swelling, diarrhea, vomiting, headache, joint pain, and chills.

In a different trial, 316 participants over 12 who had previously received the monovalent Pfizer-BioNTech COVID-19 vaccine in a two-dose primary series and a single booster also received a second booster of the bivalent Pfizer BioNTech COVID-19 vaccine. Similar to participants aged five to 11 years, people in this age group most frequently experienced the same side effects.

Because these vaccines are produced using the same method, the safety statistics gathered with the investigational bivalent vaccine (original and omicron BA.1) and with the monovalent Pfizer-BioNTech COVID-19 Vaccine apply to the bivalent model as well. The potential adverse effects of the vaccine, as well as risks of myocarditis and pericarditis, are all covered in the fact sheets for recipients and caretakers, as well as for medical professionals.