FDA panel supports switch to JN.1 for fall COVID vaccines

Vaccine advisers to the Meals and Drug Administration (FDA) at this time beneficial switching the SARS-CoV-2 pressure from the XBB.1.5 variant to JN.1 for fall vaccine formulations.

The advice marks the third remake for the COVID vaccine since 2022. The measure unanimously handed, 16 to 0. FDA officers, involved about additional evolution of JN.1, additionally requested the group to debate the potential of recommending an offshoot of JN.1, resembling KP.2, that will extra carefully match presently circulating strains. 

The Vaccines and Associated Organic Merchandise Advisory Committee (VRBPAC) was initially slated to fulfill on Could 16 however postposed its dialogue till at this time to permit time to collect extra surveillance information and different info in order that the group has essentially the most up-to-date info.

Enhancements over XBB.1.5 vaccine

JN.1 turned the dominant pressure in the US on the finish of 2023, nevertheless it continues to evolve. Offshoots resembling KP.2 and KP.3—now overshadowing the father or mother virus—have an immune-evasive spike mutation mixture that added extra complexity to strain-selection concerns. Scientists have nicknamed the spike mutations FLiRT (F for L at place 456 and R for T at place 346).

The JN.1 FLiRT variants are partly accountable for case rises in some international locations, with early US indicators displaying a slight uptick from very low sickness ranges.

In late April, the World Well being Group vaccine advisory group beneficial a change to a monovalent (single-strain) vaccine that incorporates the JN.1 antigen.

At at this time’s assembly, VRBPAC members heard from specialists on the FDA, the Facilities for Illness Management and Prevention (CDC), and vaccine producers. 

Forward of the vote, Jerry Weir, PhD, who directs the viral merchandise division within the FDA’s vaccines analysis workplace, mentioned nonclinical information from three vaccine producers counsel that up to date JN.1 lineage formulations immediate stronger neutralizing antibody responses in opposition to JN.1-descendant lineage viruses than the present monovalent XBB.1.5 vaccine. He additionally mentioned serology information from folks contaminated with JN.1 present improved antibody responses in opposition to JN.1 lineages, in contrast with sera from XBB-infected folks, although neutralizing antibody responses seem like lowered by latest mutations in lots of JN.1 lineage viruses.

Virus variety complicates discussions

After the vote, FDA officers requested advisory group members to weigh in on whether or not to pick a particular JN.1 lineage, resembling KP.2

Throughout earlier displays, a consultant from Novavax mentioned the corporate is already engaged on a JN.1 vaccine and {that a} change to a more moderen lineage might imply the corporate will not have the ability to produce vaccine in time for the US market. Protein-based vaccines have longer manufacturing timelines—about 6 months, which is analogous to flu vaccines—than mRNA vaccines do. 

Most VRBPAC members mentioned they thought JN.1 vaccines would supply good safety, they usually did not wish to shut out the Novavax possibility for people who find themselves unable to obtain an mRNA vaccine or would like getting a protein-based vaccines.

A number of members additionally mentioned they weren’t eager on “chasing variants.” Melinda Wharton, MD, MPH, affiliate director for vaccine coverage on the CDC’s Nationwide Middle for Immunization and Respiratory Ailments, mentioned variants rising when the up to date COVID vaccines are launched in August and September will not be the identical as those the committee is discussing at this time, however will most likely be associated to JN.1.

Peter Marks, MD, who directs the FDA’s Middle for Biologics Analysis and Analysis, pressed the group on whether or not it totally thought-about recommending a pressure resembling KP.2 that extra carefully matches circulating viruses. He additionally raised the potential of exploring methods to provide vaccine producers slightly extra leeway on strains to incorporate. 

Michael Nelson, MD, PhD, professor of drugs and chief of the bronchial asthma, allergy, and immunology division on the College of Virginia College of Medication, mentioned he’d want a polyvalent vaccine containing JN.1 and KP.2, however for simplicity and primarily based on reassuring neutralization information, JN.1 looks as if a pure and apparent alternative.

The group did not vote whether or not to advocate a extra particular pressure, however FDA officers will take their views, alongside the sooner vote, into consideration when making its remaining advice to vaccine.