Moderna says new booster candidate effective against Omicron subvariants

WASHINGTON — Moderna says its new COVID-19 booster candidate, which it is hoping to get approved this fall, performed well against Omicron’s latest subvariants.

The US biotech company announced earlier this month that the so-called “bivalent” vaccine, which targets the original COVID-19 strain and original Omicron BA.1, performed better against both compared to its original COVID vaccine called Spikevax.

In new results from a clinical study, the company says the booster also did well against BA.4 and BA.5, Omicron’s latest subvariants, which are becoming dominant thanks to their increased ability to evade prior immunity, and enhanced transmissibility.

The bivalent booster elicited high levels of infection-blocking antibodies against BA.4 and BA.5 both in people who were previously infected and those not previously infected.

However, even those high levels were still one-third the levels achieved against the original Omicron strain, BA.1

“We will submit these data to regulators urgently and are preparing to supply our next generation bivalent booster starting in August, ahead of a potential rise in SARS-CoV-2 infections due to Omicron subvariants in the early fall,” says Moderna CEO Stephane Bancel in a statement.