Silver Spring, Maryland – The US Food and Drug Administration unveiled its recommendations for the composition of influenza shots for the upcoming respiratory virus season. However, the task was completed without input from its independent vaccine advisers. The FDA’s Vaccines and Related Biological Products Advisory Committee had been scheduled to convene to discuss the composition of the flu shots, but the session was unexpectedly canceled in late February.
Instead of the panel, experts from within the FDA, the US Centers for Disease Control and Prevention, and the US Department of Defense came together to review surveillance data from the US and worldwide on flu viruses currently in circulation. The FDA is proposing that flu vaccines for the 2025-26 season be trivalent, providing protection against two strains of influenza A and one of influenza B.
It is anticipated that there will be a sufficient supply of approved trivalent seasonal influenza vaccines available for the upcoming virus season. The process of making flu vaccines involves careful selection of candidate viruses grown in chicken eggs, which can be quite time-consuming. Manufacturers must ensure that the selected strains are included in flu vaccines to provide an adequate supply to healthcare providers.
In order for flu vaccines to be sold in the US, they must contain strains officially selected by the FDA. The selection of strains typically follows a meeting of the World Health Organization’s Global Influenza Surveillance and Response System, involving experts from various countries twice a year in both the fall and spring to choose strains for the Northern and Southern Hemispheres.
Following the cancellation of the committee meeting, concerns arose about the timing and accessibility of flu shots for the upcoming fall season. Dr. Paul Offit, a member of the independent advisory committee, expressed relief that the FDA had released its influenza recommendation in a timely manner.
The 2024-25 flu season in the US was considered the worst in more than a decade, with millions of illnesses, hospitalizations, and deaths recorded, according to data from the CDC. The decision-making process around flu vaccines is critical to ensuring public health safety and the prevention of widespread outbreaks.