EU recommendations for 2025/2026 seasonal flu vaccine composition
Yearly updates to virus strains ensure vaccine effectiveness
NewsHumanVaccines
This news announcement was updated on 9 April 2025 to include a recommendation for a strain for seasonal live attenuated influenza vaccines.
EMA has issued recommendations for the influenza virus strains1,2 that vaccine manufacturers should include in vaccines for the prevention of seasonal influenza from autumn 2025.
Every year, EMA issues EU recommendations for the composition of seasonal influenza vaccines on the basis of observations by the World Health Organization (WHO), which are informed by regular monitoring activities on the prevalence and characteristics of different influenza viruses worldwide.
Manufacturers of live-attenuated vaccines, or egg-based trivalent vaccines should include these three virus strains for the 2025/2026 season:
- an A/Victoria/4897/2022 (H1N1)pdm09-like virus;
- an A/Croatia/10136RV/2023 (H3N2)-like virus;
- a B/Austria/1359417/2021 (B/Victoria lineage)-like virus;
Manufacturers of cell-based trivalent vaccines should include these three virus strains for the 2025/2026 season:
- an A/Wisconsin/67/2022 (H1N1)pdm09-like virus;
- an A/District of Columbia/27/2023 (H3N2)-like virus;
- a B/Austria/1359417/2021 (B/Victoria lineage)-like virus;
Previously, most authorised influenza vaccines were formulated to protect against the four main strains of influenza responsible for seasonal flu, including the strain known as B/Yamagata. However, since B/Yamagata has not been detected in circulation since March 2020, it is considered to no longer pose a threat to public health. As a result, in 2024, EMA’s Emergency Task Force (ETF) issued a statement recommending a transition from quadrivalent vaccines to trivalent vaccines that do not include the B/Yamagata strain.
The transition is on track for the season 2025/2026. If unavoidable, in order not to hamper the vaccination campaign, manufacturers of inactivated vaccines can consider producing a quadrivalent vaccine containing two influenza B virus strains for the 2025/2026 season. In that case a B/Phuket/3073/2013 (B/Yamagata lineage)-like virus in addition to the strains mentioned above is considered appropriate.
The recommendations for the influenza season 2025/2026 were endorsed by EMA's human medicines committee (CHMP) at its March 2025 plenary meeting.
Influenza viruses continuously change and evolve. The periodic replacement of the virus strains contained in influenza vaccines is therefore necessary to keep the vaccines effective.
The Agency recommends that marketing authorisation holders submit applications to change the composition of centrally authorised seasonal influenza vaccines by 9 June 2025.
1This news announcement was updated on 9 April 2025 to include a recommendation for a strain for seasonal live attenuated influenza vaccines.
2This news announcement includes the information from the EU recommendation for the seasonal influenza vaccine composition for the season 2025/2026 which was amended subsequent to CHMP adoption on 8 April 2025. Please refer to the linked document which specifies the additional strain added on 8 April 2025. Annex I of the recommendation (Reagents for vaccine standardisation) has also been updated.