The company says its first bivalent investigational vaccine, mRNA-1273.211, was efficacious against the Beta, Delta, and Omicron strains. They have identified another bivalent booster, mRNA-1273.214, which the company sees as its leading candidate for a fall 2022 scheduled dosing.
Moderna announced today its investigational bivalent vaccine candidate, mRNA-1273.211, was shown to be superior compared to its mRNA-1273 booster against the Beta, Delta, and Omicron strains 1 month after administration of its single 50 µg booster dose. And the superiority continued 6 months after administration for the Beta and Omicron variants.
The company said there was a 2.20-fold (95% CI: 1.74, 2.79) and 2.15-fold (95% CI: 1.66, 2.78) increase in the neutralizing antibody titers against Omicron with the mRNA-1273.211 booster dose compared to the mRNA-1273 booster dose at 1 month and 6 months, respectively.
“The results indicate that mRNA-1273.211 at the 50 µg dose level induced higher antibody responses than the 50 µg mRNA-1273 booster, even when additional variants of concern were not included in the booster vaccine," Moderna CEO Stéphane Bancel, said in a statement.
The company reported the vaccine was generally well tolerated. Specifically, the mRNA-1273.211 vaccine was administered to 300 participants at the 50 µg dose and 595 participants received the 100 µg dose. The former booster dosage had a similar incidence profile of solicited adverse reactions and unsolicited adverse events with the authorized mRNA-1273 booster (50 µg).
Moderna is also studying another bivalent booster candidate, mRNA-1273.214, which combines the FDA authorized COVID-19 booster with their Omicron-specific booster candidate, and the company has identified this vaccine as its leading candidate for the fall 2022 northern hemisphere booster.
"We look forward to sharing initial data on mRNA-1273.214 later in the second quarter. We believe that a bivalent booster vaccine, if authorized, would create a new tool as we continue to respond to emerging variants," Bancel said.
The company posted some of its data in a preprint on Research Gate.