WHO Announces Influenza Vaccine Recommendations for the 2025-2026 Season

Health

On March 1, 2025, the World Health Organization (WHO) unveiled its recommendations for the viral composition of influenza vaccines for the upcoming 2025–2026 influenza season in the northern hemisphere. This announcement came at the conclusion of a four-day meeting dedicated to the Composition of Influenza Virus Vaccines, an event held biannually to ensure that vaccines are effective against the ever-evolving influenza viruses.

The WHO organizes these critical consultations with a panel of experts sourced from WHO Collaborating Centres and WHO Essential Regulatory Laboratories. Together, they analyze extensive influenza virus surveillance data provided by the WHO Global Influenza Surveillance and Response System (GISRS). The insights gained during these meetings inform national vaccine regulatory agencies and pharmaceutical companies as they develop, produce, and license influenza vaccines for the forthcoming season.

The necessity for periodic updates to the viruses included in influenza vaccines stems from the virus’s dynamic nature, which can lead to new strains circulating and infecting humans. The WHO’s recommendations are essential for maintaining the efficacy of vaccines, ensuring that they target the most relevant strains.

For the 2025–2026 northern hemisphere influenza season, the WHO recommends that trivalent vaccines contain the following components:

  • For Egg-based Vaccines:

    • 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

  • For Cell Culture-, Recombinant Protein-, or Nucleic Acid-based Vaccines:

    • 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

Additionally, the recommendation for the B/Yamagata lineage component of quadrivalent influenza vaccines remains unchanged from previous years, indicating stability in that aspect of the vaccine formulation.

As the influenza season approaches, these recommendations are crucial for public health, as they guide the production of vaccines that protect millions of individuals from potentially severe influenza infections. Staying informed about these updates is essential for healthcare providers and the general public alike, as they prepare for the challenges posed by influenza viruses each year.