WASHINGTON — The Food and Drug Administration said on Thursday it had advised manufacturers of coronavirus vaccines to update their booster formulations to target the rapidly spreading Omicron subvariants known as BA.4 and BA.5. , which is now estimated to account for more than half of new virus cases in the United States.
The decision came just two days after the agency’s committee of independent vaccine experts voted overwhelmingly for regulators to adopt more advanced vaccines that would contain forms of Omicron, a recognition that current injections may no longer be sufficiently protective by then. for at least some Americans a possible fall or winter wave is coming.
“As we enter the fall and winter, it is critical that we have safe and effective vaccine boosters that can protect against circulating and emerging variants,” said Dr. Peter Marks, who oversees the FDA’s vaccine agency, said in a statement Thursday.
dr. Marks said the agency did not ask manufacturers to change the formulation for the starting doses of their coronavirus vaccines, as the current formulation “provides a basis for protection against serious consequences”.
“We expect this next year to be a transition period where this modified booster vaccine can be introduced,” he said.
The choice to target the subvariants, arguably the most transmissible coronavirus variants to date, was clouded by significant uncertainty about what form the virus could take later this year, leaving the design of Covid-19 recordings uncomfortably guesswork. for Pfizer-BioNTech and Moderna, the two major manufacturers, and the federal scientists charged with guiding them in tailoring their products.
The FDA advised manufacturers to produce a so-called bivalent vaccine together with the original coronavirus that targets BA.4 and BA.5. Some agency advisers this week said such a formulation could potentially broaden immune responses beyond an injection targeting only one form of Omicron.
Pfizer and Moderna are expected to follow the FDA’s recommendation and begin producing reformulated doses this summer, with a view to having them ready by the fall if federal regulators clear them for another booster campaign. Pfizer said Tuesday that a shot targeting its chosen sub-variants could be ready for use in early October, while Moderna expects availability in late October or early November.
Billions of dollars are at stake. The health and human services division said Wednesday it had purchased 105 million doses of the vaccine from Pfizer-BioNTech for $3.2 billion, timed for possible implementation in the fall, with options to buy up to 300 million doses. Xavier Becerra, the health secretary, called the contract “an important first step in preparing for the fall.”
Sharon LaFraniere reporting contributed.