Moderna’s strain-specific COVID booster shows promise

April 20, 2022

Moderna’s new strain-specific COVID-19 booster earned a gold star in clinical trials, after results came back showing it provided stronger protection against COVID-19, including new variants like omicron.

The company has reworked its original vaccine to target two strains of COVID-19, the original strain and the beta variant. This new, bivalent booster appears to produce more antibodies than the original vaccine, according to Moderna.

Results from a study where Moderna combined its original booster formula with an omicron-specific booster candidate showed that the shot “demonstrated superiority against beta, delta, and omicron variants one month after administration.” The 50 μg dose provided protection six months after it was given to patients, Moderna found.

The results show that the bivariate shot at the 50 μg dose level lead to higher antibody responses than the 50 μg dose of Moderna’s original booster, even when additional variants were left out of the booster vaccine, said Stéphane Bancel, CEO of Moderna.

The COVID-19 superstar will present the findings of the clinical trials of the bivariate booster, known as mRNA-1273.211, by the end of June. Moderna also has several other bivariate boosters in the works that are more specific to the COVID-19 variants as well as an omicron-specific booster.

Moderna presented the news via a company report before it was reviewed by scientists. According to a report from NPR, there are mixed reactions about the new booster. While some scientists seemed cautiously hopeful about the booster’s potential, others, like John Moore an immunologist at Weil Cornell Medicine, didn’t see the vaccine getting off the ground.

“What's here is unlikely to support the rollout of this type of bivalent vaccine — the benefits would not justify the expense and hassle,” said Moore in an email, as reported by NPR. Still, others say they are waiting until further review confirms Moderna’s findings.

If the booster moves forward, Moderna could roll out a batch by this fall, about the time when protection from previous shots will start to wear off.