A Food and Drug Administration advisory panel voted Wednesday to update the Covid vaccine formula ahead of an anticipated fall vaccination campaign, now an annual step in trying to offer better protection against circulating versions of the virus.
The unanimous vote by the 16 advisers recommends a formula aimed at fighting the JN.1 variant, which dominated infections in the United States in February, or a variant of it. In recent weeks, JN.1 has been overtaken by descendants known as KP.2 and KP.3.
In the coming weeks, the FDA is expected to formally recommend an alternative target for vaccine manufacturers for the next round of vaccines in late summer or early fall. Any decision involves some educated guesswork, since any new vaccine formulation won’t be available until months after a variant becomes dominant.
“It is becoming clear that the ideal time for a vaccine formulation decision remains unclear,” said Jerry Weir, an official in the FDA’s division of vaccines.
Dr. Peter Marks, who oversees that department, urged the committee to consider encouraging mRNA vaccine makers to focus on the latest versions of the virus in wider circulation.
“We always say we shouldn’t chase strains, but we pay an incredibly high premium for mRNA vaccines so we can have the freshest vaccines,” he said, referring to the technology used by Moderna and Pfizer. He compared choosing a vaccine to choosing fresher milk at the grocery store.
“If this develops further in the fall, are we going to regret not being a little closer?” asked Dr. Marks.
But Dr. Sarah Meyer, senior vaccine official at the Centers for Disease Control and Prevention, said targeting JN.1 was more appropriate because it was “higher up the tree” in the evolution of the coronavirus, potentially allowing vaccines to better cover the mutations. of the virus later this year.
Federal government plans for a Covid vaccination campaign, he added, had undertaken the distribution of a JN.1 option.
“I think it’s very difficult to predict what’s going to happen and where things are going to go,” he said.
The advisers’ decision on Wednesday was in line with guidance from the World Health Organization’s expert panel, which recommended in April that Covid vaccines be switched to the JN.1 formulation.
FDA advisers reviewed data showing that as of late May, KP versions of the virus accounted for about half of the coronavirus cases nationwide, a sign that they would continue to spread more widely than JN.1.
Spokesmen for Moderna and Pfizer said the companies would be ready to produce either version of the vaccine.
Novavax, which uses a different vaccine development technology, said it would target JN.1. Dr. Robert Walker, the company’s chief medical officer, said it would be effective in neutralizing KP strains.
Studies have shown that protection tends to improve as vaccines more precisely target dominant variants, according to the FDA
On Wednesday, federal officials presented an optimistic portrait of the nation’s fight against Covid. Outbreaks have been relatively low, said Natalie J. Thornburg, a CDC official, with data showing that illnesses from JN.1 were no more severe than those from earlier variants.
Fewer than 400 Covid deaths a week have been recorded recently, down from a peak of about 2,500 a week in the winter, according to initial data compiled by the CDC. Older Americans accounted for a significant portion of patients hospitalized with Covid.
Last year’s vaccination rate against the coronavirus was tepid. In March, CDC researchers reported that only 18 percent of immunocompromised adults had received the updated vaccine, which provided increased protection against hospitalization. Overall, just over 20 percent of adults received the vaccine, according to CDC data.
The lukewarm embrace of updated vaccinations also extended to nursing home residents, who were among those most likely to suffer serious illness, hospitalization or death. Data from the CDC showed that in May, about 30 percent of nursing home residents were up to date on their Covid vaccines, down from 65 percent two years ago.
