Moderna eyes fall vaccine season for omicron booster after phase 2/3 success

Moderna hopes that the successful readout from a phase 2/3 trial of its omicron-targeting COVID-19 vaccine will mean the booster shot is ready for people’s arms by late summer.

In the 437-person trial, a 50 microgram booster shot of the vaccine, dubbed mRNA-1273.214, met all pre-specified endpoints including superior neutralizing antibody response against the omicron variant one month after administration when compared to Moderna's approved Spikevax. The booster shot also increased neutralizing geometric mean titers against omicron approximately 8-fold above baseline, Moderna said in a June 8 announcement.

In addition, the booster was generally well-tolerated, with similar side effects to a 50 microgram booster dose of Spikevax, the company said.

"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,” Moderna CEO Stéphane Bancel said in a statement.

The company is submitting the preliminary data and analysis to regulators in the coming weeks with the hope of having the omicron-containing bivalent booster available in the late summer, Bancel added.

Moderna is in a race to market for an omicron-targeting booster with rivals Pfizer and BioNTech, which launched a new clinical trial to test their own vaccine for omicron in January.