The World Well being Group (WHO) in the present day introduced suggestions for the viral composition of influenza (or “flu”) vaccines for the 2026-2027 northern hemisphere influenza season. The announcement was made following a 4-day session analyzing world influenza surveillance information.
Influenza vaccine composition should be often up to date as a result of influenza viruses are continually altering. WHO’s suggestions are utilized by nationwide vaccine regulatory companies and pharmaceutical corporations around the globe to develop, produce, and license influenza vaccines for the next influenza season. This ensures that vaccines are carefully matched to the viruses anticipated to flow into, providing the very best safety towards extreme sickness and loss of life.
Held twice a yr, as soon as every for the northern and southern hemispheres, these consultations carry collectively specialists from WHO’s Collaborating Centres and Important Regulatory Laboratories of the WHO International Influenza Surveillance and Response System (GISRS) to assessment and analyze information generated by GISRS and companions.
Season after season, continually evolving influenza viruses flow into globally, exhibiting us how related our world is. Shared dangers require shared motion. WHO’s suggestions for influenza vaccine composition relaxation on the diligent, yr‑spherical work of the International Influenza Surveillance and Response System (GISRS) and companions. Because of GISRS, subsequent season’s vaccines have been up to date to counter the newest strains of influenza viruses, in flip higher defending communities.”
Dr. Tedros Adhanom Ghebreyesus, WHO Director-Normal
Seasonal influenza
In August 2025, a notably completely different variant of the A(H3N2) virus emerged (categorised as J.2.4.1, additionally known as “subclade Okay”) and unfold quickly throughout the globe. This contributed to an earlier begin to the influenza season in lots of nations, with a number of reporting larger‑than‑common ranges of exercise. ‘Subclade Okay’ accounted for nearly all of influenza viruses reported throughout areas.
General, influenza A viruses have been predominant, with different variants of A(H3N2) and A(H1N1) additionally recorded. Low ranges of influenza B viruses (B/Victoria lineage) have been detected, with no circumstances of B/Yamagata lineage viruses recorded since March 2020.
Zoonotic influenza, together with ‘chook flu’
As a part of the assessment, specialists additionally checked out influenza viruses circulating in animals, notably people who have triggered infections in people. These animal or zoonotic influenza viruses stay a big concern due to their potential to trigger pandemics.
Since 23 September 2025, following the final session, 25 human infections with zoonotic influenza have been reported to WHO from 6 nations. Nearly all of these circumstances had been uncovered to contaminated animals or to environments contaminated with influenza viruses. No human-to-human transmission was reported.
These biannual conferences embrace an in depth evaluation of those viruses and the choice of recent candidate vaccine viruses (CVVs), which will be used quickly to fabricate vaccines ought to a pandemic menace come up. At this assembly, specialists really useful the event of a brand new CVV for an A(H9N2) virus.
For vaccines to be used within the 2026-2027 northern hemisphere influenza season, WHO recommends the next:
Egg-based vaccines
an A/Missouri/11/2025 (H1N1)pdm09-like virus;
an A/Darwin/1454/2025 (H3N2)-like virus; and
a B/Tokyo/EIS13-175/2025 (B/Victoria lineage)-like virus.
Cell culture-, recombinant protein- or nucleic acid-based vaccines
an A/Missouri/11/2025 (H1N1)pdm09-like virus;
an A/Darwin/1415/2025 (H3N2)-like virus; and
a B/Pennsylvania/14/2025 (B/Victoria lineage)-like virus.
Supply:
The World Well being Group
