Flu vaccines 2024/2025: their composition

World Health Organization (WHO) published this Friday its recommendations for composition of influenza vaccines season 2024-2025 in the northern hemisphere. This was announced at a briefing after a four-day meeting on the composition of vaccines against the influenza virus. This meeting is held twice a year: once for the southern hemisphere and once for the northern hemisphere.

WHO will organize these consultations with an advisory group of experts meeting at WHO collaborating centers and WHO core regulatory laboratories to analyze influenza virus surveillance data established by the WHO Global Influenza Surveillance and Response System.

The recommendations issued are used by national vaccine regulatory agencies and pharmaceutical companies for development, production and allow flu vaccinations for next season. WHO assures that periodic updating of the viruses contained in influenza vaccines is mandatory. vaccines need to be effective due to the ever-changing nature of viruses, including those that circulate and infect humans.

WHO recommendations

In particular, WHO recommends trivalent egg-based vaccines for use in the 2022-2023 influenza season. in the northern hemisphere they contain a virus similar to A/Victoria/4897/2022 (H1N1)pdm09; virus similar to A/Thailand/8/2022 (H3N2); and B/Austria/1359417/2021-like virus (B/Victoria lineage).

For our part, in vaccines based on cell cultures or recombinants it is recommended to include a virus similar to A/Wisconsin/67/2022 (H1N1)pdm09; virus similar to A/Massachusetts/18/2022 (H3N2); and B/Austria/1359417/2021-like virus (B/Victoria lineage).

Finally, quadrivalent vaccines based on eggs or cell cultures or recombinants for use in the 2024–2025 northern hemisphere influenza season. WHO recommends inclusion of a virus similar to B/Phuket/3073/2013 (B/Yamagata lineage) as a component of the B/Yamagata lineage.