In a unanimous vote, the U.S. Food and Drug Administration’s Vaccines and Related Biological Products Advisory Committee (VRBPAC) recommended the virus strains that manufacturers should include in the 2027 Southern Hemisphere influenza vaccine. The panel, consisting of nine voting members, endorsed the same three strains—H1N1, H3N2 and influenza B—that were selected for the Northern Hemisphere season earlier this year.
Why the recommendation matters
All flu vaccines sold in the United States are trivalent, meaning they protect against three primary groups of influenza viruses: two subtypes of influenza A (H1N1 and H3N2) and one influenza B lineage. By aligning the Southern Hemisphere formulation with the Northern Hemisphere selection, the committee highlighted that the virus landscape has remained relatively stable.
Committee perspective
“I think our decision this time was very easy, and we just confirmed that not much has changed since the Northern Hemisphere strain selection,” said epidemiologist Arnold Monto, a member of the advisory panel. The committee’s recommendation is non‑binding, but the FDA typically follows its guidance.
Context for the upcoming flu season
The United States generally experiences its flu season in the fall and winter months, with peak activity from December through February, according to the Centers for Disease Control and Prevention (CDC). Preliminary data from the 2025‑26 season indicated between 32 million and 57 million illnesses, while hospitalizations reported through September 18 numbered 31,363.
For the 2026‑27 season, vaccine manufacturers anticipate producing up to 135 million doses for the U.S. market. Sanofi and CSL Seqirus have received approval to produce Southern Hemisphere formulations of their Fluzone and Afluria vaccines, respectively, within the United States.
What’s next
The FDA will review the advisory committee’s recommendation and make a final decision on the official strain selection. Once confirmed, manufacturers will begin scaling up production to meet the anticipated demand for the Southern Hemisphere market, which typically sees flu activity peak between May and October.
Health professionals encourage the public to stay informed about vaccine availability and to receive the flu shot when it becomes available, as vaccination remains the most effective tool for reducing the burden of seasonal influenza.
Original reporting: Appleton, WI News Feed (HLL/CB) — read the source article.
