Moderna, Inc., a biotechnology company pioneering messenger RNA (mRNA) therapeutics and vaccines, has announced that both of Moderna's bivalent Omicron-targeting booster candidates (mRNA-1273.214 and mRNA-1273.222) trigger a superior antibody response compared to a booster dose of mRNA-1273, the Company's prototype vaccine, against Omicron (BA.4/BA.5) in Phase 2/3 clinical trials. Both bivalent vaccines also met non-inferiority immunogenicity criteria to the original strain.
"We are pleased to see that both of our bivalent booster vaccine candidates offer superior protection against Omicron BA.4/BA.5 variants compared to our original booster, which is encouraging given COVID-19 remains a leading cause of hospitalization and death globally. In addition, the superior response against Omicron persisted for at least three months after the mRNA-1273.214 booster," said Stéphane Bancel, Moderna's Chief Executive Officer. "Our bivalent boosters also show, in research assays, neutralizing activity against BQ.1.1, an increasingly dominant emerging variant, confirming that updated vaccines have the potential to offer protection as the virus continues to evolve rapidly to escape our immunity."
In a Phase 2/3 study, a 50 µg booster dose of mRNA-1273.222 elicited a superior neutralizing antibody response against Omicron BA.4/BA.5 variants when compared to a 50 µg booster dose of mRNA-1273 in 511 previously vaccinated and boosted participants (ages 19-89 years). Participants received mRNA-1273.222 and mRNA-1273 approximately 9.5 months and 4.5 months after their prior vaccination, respectively. Pre-booster BA.4/BA.5 titers were similar between the mRNA-1273.222 and mRNA-1273 groups. The Omicron BA.4/BA.5 geometric mean titer (GMT) ratios of mRNA-1273.222 versus mRNA-1273 were 5.11 (95% CI: 4.10, 6.36) and 6.29 (95% CI: 5.27, 7.51) for participants with and without SARS-CoV-2 infection pre-booster, respectively. In all participants the GMT against Omicron BA.4/BA.5 was 4289 (95% CI: 3789.0, 4855.9) representing a 15.1-fold increase (95% CI: 13.3, 17.1) from pre-booster levels. For participants without prior infection, the GMT was 2325 (95% CI: 1321.2, 2812.7), representing a 26.4-fold increase (95% CI: 22.0, 31.9) and for those with prior infection, the GMT was 6965 (95% CI: 6043.7, 8025.4), representing a 9.8-fold (95% CI: 8.4, 11.4), increase from pre-booster levels. Importantly, results were consistent between participants aged 65 years and older and those aged 18 to 65.
In an exploratory analysis of approximately 40 participants using research assays, both bivalent vaccines demonstrated robust neutralizing activity against BQ.1.1, despite an approximately 5-fold drop in titers compared to BA.4/BA.5.
As published in the New England Journal of Medicine (NEJM), a 50 µg booster dose of mRNA-1273.214 elicited a superior neutralizing antibody response against Omicron BA.1 and Omicron BA.4/BA.5 compared to the booster dose of mRNA-1273, with superiority lasting through at least three months. In both groups, participants received the booster dose approximately 4.5 months after prior vaccination.
The frequency of adverse reactions with mRNA-1273.222 and mRNA-1273.214 were similar or lower than that of either a second or third dose of the original vaccine. Additionally, no new safety concerns were identified after approximately one month and three months of follow-up, respectively. These safety and immunogenicity data will be submitted for peer-reviewed publication and shared with regulators globally. These safety data are consistent with those recently published by the U.S. CDC and FDA in an analysis of over 211,000 individuals in the v-safe database.
