Another new version of the Covid-19 vaccine will probably be coming this fall.
The US Food and Drug Administration’s committee of independent advisers voted unanimously Wednesday to recommend that the agency tell vaccine manufacturers to update the Covid-19 shots so they will be more effective against the JN.1 lineage of the coronavirus.
The committee voted on the question, “For the 2024-2025 Formula of COVID-19 vaccines in the U.S., does the committee recommend a monovalent JN.1-lineage vaccine composition?” All 16 of the advisers voted “yes.”
The decision now goes to the full FDA. If the agency agrees with its advisory committee, the new shot will be a monovalent vaccine, offering protection against one coronavirus variant. Some previous vaccines have been bivalent, meaning they were formulated to protect against two variants.
There are a few virus variants in circulation now, but they are relatively similar.
JN.1 and its descendants KP.2 and KP.3 are the versions of the virus that are most common in the US right now, according to the US Centers for Disease Control and Prevention.
The FDA told the advisory committee Wednesday that studies have shown that currently available Covid-19 vaccines appear to be less effective against the variants that are now in circulation.
When manufacturers updated their vaccines last year to better match the variants that were in circulation then, it seemed to offer better protection. “Match does matter somewhat,” said Dr. Jerry Weir, director of the Division of Viral Products in the Office of Vaccines Research and Review at the FDA’s Center for Biologics Evaluation and Research.
“JN.1 has continued to evolve, and it makes it somewhat difficult to pick the particular specific strain to be used” this year, he told the committee. Because of manufacturing timelines, experts have to make predictions now if they want a new vaccine for fall. This is what the FDA’s committee has done for the past couple of years, and “I think it’s worked pretty well,” Weir said.
Covid-19 cases are relatively low right now. Only 3% to 4% of people who are getting tested are positive for the virus, said Dr. Natalie Thornburg, acting chief of the Laboratory Branch of the Coronavirus and Other Respiratory Viruses Division of the National Center for Immunization and Respiratory Diseases at the CDC. By comparison, at the peak of the Omicron surge in late 2021, test positivity rates were at 30%.
Hospitalization rates are also the lowest they have been since March 2020, Thornburg said.
Many people have some protection against the disease through vaccination or because they’ve had Covid before.
People who got the current Covid-19 vaccine – which was updated last fall – have protection from serious disease and death across all age groups, but as with past formulations, that protection wanes over time, Dr. Ruth Link-Gelles, vaccine effectiveness program lead with the National Center for Immunization and Respiratory Diseases, told the committee.
The advisers agreed that more people need to get updated vaccines. Only about 25% of adults have gotten the most recent shot, according to a presentation to the committee.
In only the fall and winter months last season, Covid sent more than half a million people in the US to the hospital and killed 40,000, according to data presented at the meeting.
The people most likely to get seriously ill or die were unvaccinated, Link-Gelles said, and among the children who were hospitalized, half had no underlying conditions.
“This, I think, emphasizes the need for vaccination regardless of underlying condition, status or age,” she said.
The Covid-19 vaccine manufacturers told the committee that they have done some work to prepare for the FDA’s decision on the composition of the vaccine. Animal and lab studies show that shots made by Pfizer/BioNTech, Moderna and Novavax that target the JN.1 variant seem to work well and are safe, the companies said.
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Novavax said its updated shot would need to be the JN.1 version because its protein vaccine takes about six months to make, and that’s the version it has been working on. The company said it could get the shot to US warehouses by August.
Pfizer and Moderna’s mRNA vaccines can be developed more quickly, and those companies said they could have either a JN.1 shot or a KP.2 shot ready for fall. Moderna said it could supply the US market by mid-August, and Pfizer said its shot could be immediately ready upon approval.
The committee discussed but did not vote on whether the shot should match JN.1 or KP.2. Most of the members preferred JN.1 so Americans would have an option to get an mRNA vaccine or a more traditional protein-based vaccine.
Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, told the committee that the FDA will take these recommendations into consideration as it makes its final choice.
