EU recommendations for 2026/2027 seasonal flu vaccine composition
Annual updates to virus strains ensure vaccines stay effective
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This news announcement was updated on two occasions. On 7 May 2026, it was updated to include additional recommendations for strains for seasonal egg-derived and live-attenuated influenza vaccines. On 26 May 2026, it was further updated to include recommendations for suitable A/H3N2 virus for seasonal cell-derived vaccines and suitable B-lineage virus for seasonal live attenuated influenza vaccines. Annex I (Reagents for vaccine standardisation) was also updated.
EMA has issued recommendations for the influenza virus strains (see note) that vaccine manufacturers should include in vaccines for the prevention of seasonal influenza from autumn 2026.
Please refer to the latest version of the document in the Related documents section. The document specifies the additional strains and the updated annex I of the recommendation (Reagents for vaccine standardisation).
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 vaccines should include these three virus strains for the 2026/2027 season:
- an A/Missouri/11/2025 (H1N1)pdm09-like virus;
- an A/Darwin/1454/2025 (H3N2)-like virus;
- a B/Tokyo/EIS13-175/2025 (B/Victoria lineage)-like virus.
Manufacturers of cell-based vaccines should include these three virus strains for the 2026/2027 season:
- an A/Missouri/11/2025 (H1N1)pdm09-like virus;
- an A/Darwin/1415/2025 (H3N2)-like virus;
- a B/Pennsylvania/14/2025 (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, there is no EU recommendation for a B/Yamagata strain in seasonal influenza vaccines for the 2026/2027 influenza season, which is in line with the respective WHO recommendation regarding the composition of vaccines for 2026/2027.
In case quadrivalent vaccines are still required (e.g. in regions where the transition to trivalent vaccines has not been finalised yet), vaccine manufacturers of inactivated vaccines can consider producing a quadrivalent vaccine containing two influenza B virus strains for the 2026/2027 season. For these vaccines it is proposed to follow WHO recommendations from previous years for the B/Yamagata strain, i.e. a B/Phuket/3073/2013 (B/Yamagata lineage)-like virus.
The recommendations for the influenza season 2026/2027 were endorsed by EMA's human medicines committee (CHMP) at its March 2026 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 15 June 2026.
Note: This news announcement includes the information from the EU recommendation for the seasonal influenza vaccine composition for the season 2026/2027 which was amended on two occasions: subsequent to CHMP adoption on 5 May 2026 and on 21 May 2026.