FDA’s Vaccines and Related Biological Products Advisory Committee recommended that regulators drop the quadrivalent influenza vaccines used for roughly the past decade or so in favor of a trivalent replacement.

The new formulation, which is expected to be introduced for the 2024–2025 influenza season, would eliminate protection against a family of viruses that no longer pose a threat. The B/Yamagata viruses have not been documented anywhere in the world since early 2020.

While panel members acknowledge the need for intentional messaging around the change, which a Sanofi representative worried could be interpreted unfavorably by a public that is gravitating away from immunizations, some suggested the formulation adjustment could pump up public confidence in both vaccines and the process.