British drug regulators on Monday approved a two-pronged vaccine from Moderna that’s designed to fight both the original version of the coronavirus and the omicron variant.
The decision makes the U.K. the first country to clear a COVID-19 booster that’s been specifically tailored to a newer form of the virus. While the original shots, like Moderna’s Spikevax, remain strongly effective at preventing hospitalization and death, they’ve had a harder time warding off infections from omicron and its subvariants.
Public health officials are hoping newer shots, like Moderna’s so-called bivalent vaccine, will prove more protective. But the omicron-fighting component in Moderna’s shot was tailored against an older version of the variant, not the currently circulating strains known as BA.4 and BA.5.
“The virus, SARS-CoV-2, is continually evolving in order to evade the immunity provided by vaccines,” Munir Pirmohamed, chair of the advisory panel to the UK’s Medicines and Healthcare products Regulatory Agency, said in a statement. “This novel bivalent vaccine represents the next step in the development of vaccines to combat the virus, with its ability to lead to a broader immune response than the original vaccine.”
The approval decision was based on a 437-patient trial that assessed the shot’s safety and ability to spur an immune response. When compared to SpikeVax, the dual-acting shot stimulated the production of more virus-fighting antibodies against omicron while maintaining its potency against the ancestral strain. It’s unclear whether the bivalent shot is more protective against infection.
A separate U.K. agency called the Joint Committee on Vaccination and Immunization will decide who should receive the bivalent booster first. The National Health Service is currently offering boosters of the original shot to previously vaccinated people who are at least 16 years old, as well as some adolescents with weakened immune systems. Those over 75 years of age, or immunocompromised people 12 and older, can get a fourth shot.
The U.K.’s decision is a departure from the stance the Food and Drug Administration has taken in the U.S. Though an advisory panel supported an omicron-specific component in the next round of boosters, many of them argued newer shots should be tailored to BA.4 or BA.5. The FDA has since recommended developers update their vaccines to target those subvariants.
Speaking to an advisory committee in June, executives from Moderna and Pfizer said dual-acting boosters with a BA.4 or BA.5 could be available in large volumes in October and November, although they would first need to undergo regulatory review before they could be administered.
U.S. officials have authorized third and fourth shots to a wider group of people than the U.K. has, with everyone 5 years of age and older eligible for at least one booster. Those 50 years and older, and immunocompromised people 12 and older, can get a fourth shot.
Separately, Novavax on Monday asked the FDA to authorize its COVID-19 vaccine as a booster shot in people 18 and older. The shot is only available as a primary series to those who haven’t yet been vaccinated.