WHO Announces Influenza Vaccine Composition for 2025–2026 Northern Hemisphere Season

The meeting serves as a crucial platform for analyzing surveillance data collected by the WHO Global Influenza Surveillance and Response System (GISRS).

The World Health Organization (WHO) has released its official recommendations for the viral composition of influenza vaccines for the 2025–2026 influenza season in the northern hemisphere. This announcement was made at the conclusion of a four-day biannual meeting on the Composition of Influenza Virus Vaccines, which brings together leading global influenza experts. The meeting serves as a crucial platform for analyzing surveillance data collected by the WHO Global Influenza Surveillance and Response System (GISRS).

These recommendations will guide national vaccine regulatory agencies and pharmaceutical manufacturers in the development, production, and licensing of influenza vaccines for the upcoming season. Due to the continuous evolution of influenza viruses, periodic updates are necessary to ensure vaccine effectiveness against circulating strains.

Recommended Influenza Vaccine Composition for 2025–2026

Trivalent Influenza Vaccines

The WHO has recommended the following strains for inclusion in trivalent vaccines:

Egg-based 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

Cell culture-, recombinant protein-, or nucleic acid-based vaccines:

• A/Wisconsin/67/2022 (H1N1)pdm09-like virus
• A/District of Columbia/27/2023 (H3N2)-like virus
• B/Austria/1359417/2021 (B/Victoria lineage)-like virus

Quadrivalent Influenza Vaccines

For quadrivalent vaccines, the WHO recommends the inclusion of an additional B/Yamagata lineage component:

• B/Phuket/3073/2013 (B/Yamagata lineage)-like virus

Significance of the Updates

These recommendations are based on extensive global influenza virus surveillance data. WHO Collaborating Centres and WHO Essential Regulatory Laboratories assess genetic and antigenic characteristics of circulating influenza viruses to determine the most suitable strains for upcoming vaccines.

The continuous adaptation of influenza vaccine compositions ensures better protection against influenza-related morbidity and mortality. Countries and vaccine manufacturers will now work towards incorporating these recommendations into their national immunization programs to enhance global public health preparedness.

For further details, please visit the WHO website or contact your local public health authorities.