The composition of the next influenza vaccine will include the A(H1N1)pdm09, A(H3N2) and B/Victoria viruses, the WHO announced in a statement, following a four-day meeting in which global influenza surveillance data were analysed and experts recommended the development of a new vaccine candidate virus (VCV), A(H9N2), which could be rapidly used to manufacture vaccines should a pandemic threat emerge.

Experts analysed influenza viruses circulating in animals, particularly those that have caused human infections, which remain “a significant concern” due to their potential to cause a pandemic.

“Since 23 September 2025, after the last consultation, 25 human infections with zoonotic influenza have been reported to the WHO by six countries. Most of these cases had been exposed to infected animals or environments contaminated with influenza viruses,” but no human-to-human transmission has been reported, the health authority said.

Virus evolution

“Season after season, constantly evolving influenza viruses circulate globally, showing us how interconnected our world is. Shared risks require shared actions,” said WHO Director-General Tedros Adhanom Ghebreyesus, quoted in the statement.

The Director-General explained that the WHO recommendations for the composition of the influenza vaccine are based on the diligent work, throughout the year, of the Global Influenza Surveillance and Response System (GISRS) and its partners.

“Thanks to GISRS, next season’s vaccines have been updated to combat the latest strains of influenza viruses, thus better protecting communities,” emphasises Tedros Adhanom Ghebreyesus.

Recomendations

WHO recommendations are used by national vaccine regulatory agencies and pharmaceutical companies worldwide to develop, produce, and license influenza vaccines for the upcoming flu season.

“This ensures that vaccines are compatible with the viruses expected to circulate, offering the best possible protection against serious illness and death,” the WHO emphasises.