Moderna Announces Bivalent Vaccine Booster Effective Against Omicron

This morning, Moderna shared positive data from clinical trials for mRNA-1273.214, their new bivalent COVID-19 vaccine booster. The booster targets multiple COVID-19 variants that may have escaped the protection of the original Moderna mRNA-1273 (Spikevax) vaccine, including Omicron.

At 1 month after administration, a 50-µg booster dose of mRNA-1273.214 met all pre-specified trial endpoints, including a significant neutralizing antibody response against Omicron.

In February 2021, Moderna announced plans to update its booster vaccine with monovalent and bivalent candidates to target multiple developing variants of concern. Bivalent boosters simultaneously address 2 viral strains, making them a useful tool against all current and future circulating COVID-19 variants.

In April 2022, Moderna initially reported positive results for 2 bivalent booster candidates, mRNA-1273.211 and mRNA-1273.214. The former demonstrated superiority against the Beta, Delta, and Omicron variants of concern at 1 month after administration, with durable protection against Beta and Omicron for at least 6 months.

mRNA-1273.214 elicits significantly higher levels of neutralizing antibody titers, leading investigators to predict protection against Omicron will remain robust over time.

"Looking at these data alongside the durability we saw with our first bivalent booster candidate, mRNA-1273.211, we anticipate more durable protection against variants of concern with mRNA-1273.214, making it our lead candidate for a Fall 2022 booster,” said Stéphane Bancel, the Chief Executive Officer of Moderna. “We are submitting our preliminary data and analysis to regulators with the hope that the Omicron-containing bivalent booster will be available in the late summer.” 

mRNA-1273.214 met all primary endpoints in the phase 2/3 trial, with a booster dose increasing protection against Omicron 8-fold above baseline levels.

Among seronegative trial participants, the neutralizing geometric mean titers (GMT) against the ancestral strain of COVID-19 was 5977 for mRNA-1273.214, compared to mRNA-1273’s GMT of 5649. Against Omicron, GMT for mRNA-1273.214 was 2372, and mRNA-1273 had GMT of 1473.

The mRNA-1273.214 booster was generally well-tolerated in the 437 study patients, with the majority of side effects comparable to a 50-µg booster dose of the original mRNA-1273 vaccine.

Moderna reported plans to submit these interim analyses and data in the coming weeks for regulators for review.