FDA Panel Backs New COVID Booster Focusing Only on Variants

June 15, 2023 – A panel of advisers to the FDA unanimously agreed today that the next COVID-19 vaccines should target the XBB variants of the SARS-CoV-2 virus now in circulation in the United States, but questioned whether the population as a whole needs booster shots and how often they should be given.

The Vaccines and Related Biological Products Advisory Committee of the FDA voted 21-0 in favor of the recommendation about the strain to be used in the next crop of vaccines.

In the briefing document for the meeting, FDA staff said the available evidence suggests that a monovalent (single-strain) XBB-lineage vaccine “is warranted” for the 2023-2024 vaccination campaign and would replace the current bivalent vaccine, which targets the original version of the virus and two strains from the Omicron variant.

FDA staff also noted how such a shift would be in line with the World Health Organization toward targeting the XBB family of subvariants. European regulators have done this as well. 

The FDA is not obligated to act on the panel’s recommendations. But the agency often does and is highly likely to do so in this case. Vaccine companies will need the recommendation from the FDA to begin making vaccines for the fall.

New Shot Every Year?

The FDA asked its expert panel to vote only on the question about the makeup of future vaccines in terms of which strain to include. 

But panelists also raised other questions during the meeting, including concerns about moves toward tying COVID vaccinations into the model of annual flu shots. 

Paul Offit, MD, director of the Vaccine Education Center at the Children’s Hospital of Philadelphia, argued for greater focus on the response of T cells after vaccination, even in light of the already recognized waning of antibody protection. 

In a recent Substack article, Offit called T cells the “unsung hero” of the pandemic. They take longer to develop after infection than the antibodies that first attack the virus, but immune memory cells called B and T cells “are long-lived,” and their “protection against severe disease often lasts for years and sometimes decades.” 

Offit said he was concerned about using a blanket approach for future recommendations for COVID vaccinations, following the one now in place for influenza vaccines. The CDC recommends flu shots for everyone 6 months and older, with rare exceptions. 

Instead, future COVID vaccination recommendations should be more finely tuned in terms of additional shots for those already vaccinated, Offit said.

“We need to continue to define who those high-risk groups are and not make this a recommendation for everybody every season,” he said.