FDA Authorizes Pfizer, Moderna Updated COVID-19 Boosters

The approval of the updated bivalent boosters is based on data from clinical studies of the omicron variant BA.1, and animal data on the omicron BA.4 and BA.5 variant.

The FDA has amended the emergency use authorizations (EUAs) of both the updated Moderna and the Pfizer/BioNTech COVID-19 booster vaccines that include the omicron variants. The updated boosters are bivalent vaccines and contain two messenger RNA (mRNA) components, one of the original strain of the SARS-CoV-2 and the BA.1, BA.4 and BA.5 omicron variant.

The Moderna booster is a single dose in people 18 years of age and older. The Pfizer-BioNTech booster is a single dose in people 12 years of age and older. People are eligible for the updated boosters if it’s been at least two months since they have had most recent booster or the primary vaccination series.

“The COVID-19 vaccines, including boosters, continue to save countless lives and prevent the most serious outcomes (hospitalization and death) of COVID-19,” FDA Commissioner Robert M. Califf, M.D., said in a press release. “As we head into fall and begin to spend more time indoors, we strongly encourage anyone who is eligible to consider receiving a booster dose with a bivalent COVID-19 vaccine to provide better protection against currently circulating variants.”

For each bivalent COVID-19 vaccine, the FDA based its decision on the totality of available evidence, including extensive safety and effectiveness data for each of the monovalent mRNA COVID-19 vaccines, safety and immunogenicity data obtained from a clinical study of the booster with both the original virus and the omicron variant BA.1 lineage, and nonclinical data on the BA.4 and BA.5 lineages of the omicron variant.

Pfizer had indicated last week when it submitted its EUA that the updated booster would be available to ship immediately. Moderna indicated that its updated booster would be ready to ship in the next few days, the company said in a press release.

Related: Pfizer Submits EUA for Updated COVID-19 Booster

Related: Moderna Completes Application for Updated COVID-19 Booster

Pfizer plans to submit an application for an omicron-adapted bivalent vaccine booster for children 5 through 11 years of age in early October, company officials said in a press release. Additionally, Pfizer and BioNTech are working with the FDA to prepare an application for an omicron-adapted bivalent vaccine in children 6 months through 4 years of age.

Pfizer also recently provided updated efficacy results from a phase 2/3 trial evaluating a primary three-dose series in children 6 months through 4 years of age. Emergency use authorization for this age group was granted by the FDA in June 2022, and an application for conditional Marketing Authorization in this age group is under review by the European Medicines Agency (EMA).

Updated analysis in trials following a three-dose regimen showed 73.2% vaccine efficacy among children ages 6 months through 4 years. The vaccine efficacy remained consistently above 70% in both the 6 through 23 months and the 2 through 4 years age groups. Consistent with the time period when the cases occurred, sequencing of viral RNA from illness visit nasal swabs indicated that observed cases were primarily caused by omicron BA.2. Omicron BA.4 and BA.5 strains were emerging during the period of the study, with only a few cases accrued and efficacy results against these strains were inconclusive.