The World Health Organization (WHO) has released its recommendations for the viral composition of influenza vaccines for the 2025–2026 season in the northern hemisphere. The decision was made after a four-day meeting with an advisory group of experts, who analyzed data from the WHO’s Global Influenza Surveillance and Response System.
Due to the rapidly evolving nature of influenza viruses, periodic updates are necessary to ensure vaccine effectiveness. The WHO recommends two types of vaccines for the 2025–2026 season: egg-based and cell culture-, recombinant protein- or nucleic acid-based ones. Both will contain specific strains of the flu virus, including:
For trivalent vaccines:
– A/Victoria/4897/2022 (H1N1)pdm09-like virus
– A/Croatia/10136RV/2023 (H3N2)-like virus
– B/Austria/1359417/2021 (B/Victoria lineage)-like virus
For quadrivalent vaccines:
– An additional strain, a B/Yamagata lineage component, which remains unchanged from previous recommendations: B/Phuket/3073/2013.
These recommendations will guide the development and production of influenza vaccines for the upcoming season.
Source: https://www.who.int/news/item/28-02-2025-recommendations-announced-for-influenza-vaccine-composition-for-the-2025-2026-northern-hemisphere-influenza-season