The World Health Organization (WHO) today announced its advisory group’s recommendations for the Southern Hemisphere’s 2026 flu vaccines, which swap out both the H1N1 and H3N2 strains in the current vaccines for the Northern Hemisphere as well as those for the Southern Hemisphere’s last flu season.
The change in influenza strains affects both the egg- and cell-based vaccines. However, the H3N2 picks are different for the two vaccines. For egg-based vaccines, the experts recommend an A/Singapore/GP20238/2024 (H3N2)–like virus, and for cell-based vaccines, they went with an A/Sydney/1359/2024 (H3N2) –like virus.
Meanwhile, their influenza B Victoria lineage pick is the same one they recommended for the current Northern Hemisphere vaccine and last season’s Southern Hemisphere vaccine. The group did not make a recommendation for the influenza B Yamagata lineage, which has not circulated since March 2020.
No new pandemic-preparedness flu strain picks
The WHO’s flu vaccine composition advisory group meets twice a year, in February to weigh in on Northern Hemisphere recommendations and in September to give advice on Southern Hemisphere vaccines. At both meetings, they also assess the latest zoonotic flu developments and gauge if new candidate pandemic-preparedness flu vaccine strains are needed. They didn’t recommend any new strains at this week’s meeting.
The Food and Drug Administration (FDA) vaccine advisory group is slated to meet on October 9 to discuss strain selection for the 2026 Southern Hemisphere. The Vaccines and Related Biological Products Advisory Committee (VRBPAC) is also slated to make recommendations on the Center for Biologics Evaluation and Research’s allergen-standardization program.
