On Aug. 26, 2022, Pfizer and BioNTech announced they had completed a submission to the European Medicines Agency for a booster dose of an Omicron BA.4/BA.5-adapted bivalent COVID-19 vaccine for individuals 12 years of age and older. This application for a variation of the conditional marketing authorization (cMA) follows guidance from the EMA and International Coalition of Medicines Regulatory Authorities (ICMRA) to work towards introducing Omicron-adapted bivalent vaccines.

The bivalent vaccine contains 15-µg of mRNA encoding the wild-type spike-protein of SARS-CoV-2, which is present in COMIRNATY^® (the original Pfizer-BioNTech COVID-19 Vaccine) and 15-µg of mRNA encoding the spike protein of the Omicron BA.4/BA.5 variants. With the exception of the addition to the mRNA of the Omicron BA.4/BA.5 spike protein sequence, all other components of the vaccine remain unchanged. Pre-clinical data showed a booster dose of Pfizer and BioNTech’s Omicron BA.4/BA.5-adapted bivalent vaccine generated a strong neutralizing antibody response against Omicron BA.1, BA.2 and BA.4/BA.5 variants, as well as the original wild-type strain.

In addition to the pre-clinical, quality and manufacturing data for the Omicron BA.4/BA.5 adapted bivalent vaccine, the submission is supported by safety, tolerability and immunogenicity data from a Phase 2/3 trial of a 30-µg booster dose of their Omicron BA.1-adapted bivalent vaccine, which combines 15-µg of mRNA encoding the wild-type spike protein of SARS-CoV-2 with 15-µg of mRNA encoding the spike protein of the Omicron BA.1 variant. The companies have also provided safety data from clinical trials evaluating multiple variant-adapted vaccine candidates based on previous variants of concern (e.g., Alpha, Beta and Delta variants).