Update 6/13/24: The FDA has updated its guidance to manufacturers, asking them to use the KP.2 strain from the JN.1 lineage "if feasible" to better match circulating strains. It said it does not anticipate the change to cause a delay in vaccine availability.
Update 6/7/24: The FDA has advised vaccine manufacturers to use the JN.1 strain for the 2024-'25 COVID-19 vaccines, following the recommendation of its vaccine committee. For the latest news on COVID-19, visit http://bit.ly/AAPNewsCOVID19.
A federal vaccine committee recommends updating COVID-19 vaccines this fall to better match circulating virus strains.
The Food and Drug Administration’s (FDA’s) Vaccine and Related Biological Products Advisory Committee (VRBPAC) voted 16-0 in favor of a monovalent vaccine from the omicron JN.1 lineage.
The FDA will consider the committee’s input and make a final decision on vaccine composition. It will be up to the Centers for Disease Control and Prevention (CDC) to decide whether everyone should get an updated vaccine or only people in certain high-risk categories. The CDC’s vaccine committee is scheduled to discuss the issue June 27.
The 2023-’24 vaccine is composed of an omicron XBB.1.5 virus, and data presented Wednesday showed it provided protection against symptomatic infection and hospitalization. However, protection wanes over time and variants are continuing to change.
The omicron JN.1 lineages replaced XBB as the dominant strains this past winter. In the spring, its sublineage KP.2 became dominant, making up an estimated 28.5% of circulating strains, according to CDC modeling. Other circulating strains include KP.3 (12.7%), JN.1.7 (9.2%) and KP.1.1 (9.2%).
Vaccine manufacturers Moderna, Pfizer and Novavax presented data Wednesday from studies in mice showing their JN.1 vaccine formulations elicit stronger neutralizing antibody responses against JN.1 and its sublineages than the current XBB vaccines.
The FDA committee agreed a JN.1 lineage vaccine would be best for the upcoming 2024-25 respiratory virus season. The recommendation falls in line with that of the World Health Organization.
After voting on the change, the FDA committee discussed whether to specifically recommend a JN.1 sublineage like KP.2, but ultimately agreed on the broader JN.1.
“We can’t predict which variants are going to emerge over the coming months, and it may very well not be any of the ones we’re talking about today,” said Melinda Wharton, M.D., M.P.H., associate director for vaccine policy at the CDC’s National Center for Immunization and Respiratory Diseases. “But they are likely related to JN.1 so having a vaccine that’s the trunk of the tree rather than the branches makes sense to me. I think the chances of having cross protection are greater.”
Novavax only has prepared a broad JN.1 vaccine, so choosing KP.2 may have meant two different formulations, which some said could cause confusion. Several committee members said it is important to have Novavax’s protein subunit vaccine as an option for people who don’t want an mRNA vaccine like those from Moderna and Pfizer.
Manufactures all said they anticipate an adequate supply of JN.1 vaccine this fall.
Uptake of the 2023-'24 COVID-19 vaccines has been low — 6% for children ages 6 months-4 years, 13% for ages 5-11 years, 18% for ages 12-17 years and 23% for adults, according to the CDC.
Resources
- CDC clinical considerations for administering COVID-19 vaccines
- AAP COVID vaccination resources
- AAP pediatric COVID-19 vaccine dosing quick reference guide
- CDC COVID Vaccination Field Guide
- AAP/Health and Human Services COVID vaccine toolkit
- Information for parents on COVID vaccines from HealthyChildren.org
