The World Health Organization (WHO) has released its recommendations for the viral composition of influenza vaccines to be used in the southern hemisphere’s 2026 flu season.
The announcement followed a four-day Consultation on the Composition of Influenza Virus Vaccines, with details shared at a public Information Meeting.
For trivalent vaccines, WHO recommends the following strains:
Egg-based vaccines:
A/Missouri/11/2025 (H1N1)pdm09-like virus
A/Singapore/GP20238/2024 (H3N2)-like virus
B/Austria/1359417/2021 (B/Victoria lineage)-like virus
Cell culture, recombinant protein or nucleic acid-based vaccines:
A/Missouri/11/2025 (H1N1)pdm09-like virus
A/Sydney/1359/2024 (H3N2)-like virus
B/Austria/1359417/2021 (B/Victoria lineage)-like virus
As with previous updates since September 2023, WHO’s advisory committee concluded that a B/Yamagata lineage antigen should no longer be included.
Full details are available on the WHO website: WHO recommendations for 2026 southern hemisphere influenza vaccines
