On Jun. 24 2022, Pfizer and BioNTech announced positive data evaluating the safety, tolerability, and immunogenicity of two Omicron-adapted COVID-19 vaccine candidates: one monovalent and the other bivalent, a combination of the Pfizer-BioNTech COVID-19 Vaccine and a vaccine candidate targeting the spike protein of the Omicron BA.1 variant of concern.

Data from the Phase 2/3 trial found that a booster dose of both Omicron-adapted vaccine candidates elicited a substantially higher immune response against Omicron BA.1 as compared to the companiesﾒ current COVID-19 vaccine.