Food and Drug Administration officials said they will make a decision at a later date.
On May 22, Food and Drug Administration advised directly institutions of COVID-19 vaccine manufacturers to update their targets for stocks.
The Vaccine and Related Biological Products Advisory Committee unanimously voted to advise regulators to update the vaccine to target a single strain, one of the JN.1 subvariants.
The Moderna and Pfizer vaccines currently contain formulations of KP.2 strains, while the Novavax vaccine targets the JN.1 variant.
These versions of the vaccine have been available since 2024 when it was cleared without testing data.
Representatives from Moderna, Pfizer and Novavax told panel members before the vote that Covid-19 is still a problem and that immunological testing in humans showed that the vaccine could provide protection to recipients including Lp.8.1, a JN.1 subvariant.
Animal studies showed that the immune response with the LP.8.1 formulation was slightly better.
LP.8.1 has caused about 70% of Covid-19 cases in recent weeks, despite an increase in other subvariants, according to the Centers for Disease Control and Prevention’s Estimation.
The FDA has convened a meeting for “continuous antigenic drift” of Covid-19, officials said in the presentation.
Dr. Vinay Prasad, director of the FDA’s Center for Biological Evaluation and Research, said at the start of the meeting:
Prasad said Thursday that FDA officials would like to “give people a little more time to digest their policies” and that they are interested in feedback.
The Pfizer and Modern vaccines are available to people over six months without restrictions.
The World Health Organization says that vaccines currently available are still appropriate as “there is not significantly reduced cross-reactivity to LP.8.1.” The organization also states that vaccines targeting LP.8.1 are a “appropriate alternative.”
Some members of the committee said Thursday they supported updating the vaccine to target LP.8.1 as it is dominant at this point.
“We’re choosing antigens for the future, not antigens for the moment,” Dr. Eric Rubin, editor-in-chief of the New England Journal of Medicine, said after the vote.
“This may not be the variant we’ll end up in the fall, but this is probably the closest we can get,” added Dr. Archana Chatterjee, dean of the University of Medicine at Chicago.
Several members have expressed support to direct vaccine makers to continue targeting strains they have already targeted.
“Based on the whole evidence and other considerations, I agree to staying at the current JN.1 or KP.2 this season,” said CDC executive and member Dr. Sarah Meyer.
When several panelists expressed concern that recommendations for renewal of the formulation could lead to a smaller population of people who can receive the vaccine considering the announcement of the FDA this week, FDA officials declined to say whether it was an option.
“What we do at our agency is to come back today and see what we said today. Try to come up with all the recommendations we can for manufacturers and public health,” FDA official Jerry Weir said after the vote.