On Aug. 15, 2022, Moderna announced that the Medicines and Healthcare products Regulatory Agency (MHRA) in the UK had granted conditional authorization for the use of the Omicron-containing bivalent COVID-19 booster vaccine, mRNA-1273.214 (Spikevax Bivalent Original/Omicron) as a booster dose for active immunization to prevent COVID-19 caused by SARS-CoV-2 in individuals 18 years of age and older.

Spikevax Bivalent Original/Omicron is a next-generation bivalent vaccine that contains mRNA-1273 (Spikevax) and a vaccine candidate targeting the Omicron variant of concern (BA.1).

The decision from the MHRA is based on clinical trial data from a phase 2/3 trial, in which mRNA-1273.214 met all1 primary endpoints, including superior neutralizing antibody response against Omicron (BA.1) when compared to a 50 μg booster dose of mRNA-1273 in baseline seronegative participants. A booster dose of mRNA-1273.214 increased neutralizing geometric mean titers (GMT) against Omicron approximately 8-fold above baseline levels. In addition, mRNA-1273.214 elicited potent neutralizing antibody responses against the Omicron subvariants BA.4 and BA.5 compared to the currently authorized booster (mRNA-1273) regardless of prior infection status or age.