Pfizer gets USFDA emergency use nod for Omicron BA.4/BA.5-adapted bivalent COVID booster in children under 5 years

The EUA is based on data from substudies within the companies’ Phase 1/2/3 study (NCT05543616) evaluating the safety, tolerability and immunogenicity of a fourth dose of the bivalent vaccine in children 6 months through 4 years of age (n=300). Safety and immunogenicity were assessed in a subset of study participants 6 months through 4 years of age (n=60), demonstrating that a booster (fourth) dose of the Omicron BA.4/BA.5-adapted bivalent vaccine elicited improved Omicron BA.4/BA.5-neutralizing antibody responses compared to participants who received three doses of the companies’ original vaccine. The safety and tolerability profile of the bivalent vaccine was similar to that of the original vaccine.

Based on the latest real-world evidence, Omicron BA.4/BA.5-adapted bivalent vaccines appear to be protective against symptomatic COVID-19 disease in adults caused by both BA.4/BA.5 and XBB Omicron sublineages, the latter of which currently account for more than 85% of COVID-19 cases in the U.S.  Additional real-world evidence collected between September 2022 and December 2022 shows that among older adults, receiving an mRNA-based bivalent booster provided greater vaccine effectiveness against COVID-19 hospitalization compared to receiving two or more doses of the companies’ original wild-type vaccine administered two months earlier. This was observed during a time when different Omicron sublineages were circulating, including XBB.1.5 which started to circulate in the second half of December.

Pfizer and BioNTech have also submitted an application to the European Medicines Agency (EMA) to extend the Omicron BA.4/BA.5-adapted bivalent vaccine’s marketing authorization to include use in children 6 months through 4 years of age as both primary series (all three doses) and booster vaccination (fourth dose). Currently, the bivalent vaccine is authorized in the European Union (EU) as a booster dose for ages 5 years and older. The companies plan to submit applications to other regulatory authorities worldwide for the use of their Omicron BA.4/BA.5-adapted bivalent vaccine among children under 5 years of age.

The Pfizer-BioNTech COVID-19 Vaccines (COMIRNATY) are based on BioNTech’s proprietary mRNA technology and were developed by both BioNTech and Pfizer. BioNTech is the Marketing Authorization Holder for BNT162b2 (Original) and BNT162b2 Bivalent (Original/Omicron BA.4/BA.5) in the United States, the European Union, the United Kingdom, Canada and other countries, and the holder of emergency use authorizations or equivalents in the United States (jointly with Pfizer) and other countries.