The European Medicines Agency has issued its annual recommendations for the influenza virus strains to be included in seasonal vaccines from autumn 2026, specifying separate strain compositions for egg-based, cell-based, and live-attenuated vaccine platforms.
The recommendations were initially endorsed by EMA’s human medicines committee (CHMP) in March 2026 and subsequently updated on 7 May and 26 May 2026 to provide additional guidance on specific strains across vaccine types.
Strain Composition
Manufacturers of live-attenuated and egg-based vaccines should include the following three strains for the 2026/2027 season: an A/Missouri/11/2025 (H1N1)pdm09-like virus, an A/Darwin/1454/2025 (H3N2)-like virus, and a B/Tokyo/EIS13-175/2025 (B/Victoria lineage)-like virus.
For cell-based vaccines, the recommended strains are an A/Missouri/11/2025 (H1N1)pdm09-like virus, an A/Darwin/1415/2025 (H3N2)-like virus, and a B/Pennsylvania/14/2025 (B/Victoria lineage)-like virus.
Shift to Trivalent Vaccines
The 2026/2027 recommendations continue the move away from quadrivalent vaccines. The B/Yamagata influenza lineage, previously included as a fourth strain, has not been detected in circulation since March 2020 and is no longer considered a public health threat. Consequently, the EU does not recommend a B/Yamagata strain for the upcoming season, aligning with WHO guidance.
For regions where the transition to trivalent vaccines has not yet been completed, manufacturers of inactivated vaccines may still produce quadrivalent formulations. In such cases, the WHO-recommended B/Phuket/3073/2013 (B/Yamagata lineage)-like virus should be used.
Annual Process and Timeline
Every year, EMA formulates its vaccine composition recommendations based on worldwide surveillance data collected by the World Health Organization. Influenza viruses evolve continuously, making regular updates to vaccine strains essential for maintaining effectiveness.
Alongside the strain recommendations, EMA updated Annex I (Reagents for vaccine standardisation), which sets specifications for the reagents used in vaccine quality control.
Marketing authorisation holders must submit applications to update the composition of centrally authorised seasonal influenza vaccines by 15 June 2026.
Source: EMA News
