The EMA has published recommendations on the influenza strains that vaccine manufacturers should include in vaccines to protect against seasonal influenza starting in autumn 2024.Each year, the EMA publishes EU recommendations on the composition of seasonal influenza vaccines based on observations from the World Health Organization (WHO), which They are based on regular campaigns to monitor the prevalence and characteristics of different influenza viruses around the world.
EMA Emergency Task Force (ETF) issued a statement It is recommended to transition from the quadrivalent vaccine to the trivalent vaccine that does not contain the B/Yamagata component.
Currently, most authorized influenza vaccines are quadrivalent, meaning they are formulated to protect against the four main strains that cause seasonal influenza: A(H1N1)pdm09 and A(H3N2), B/Victoria, and B /Yamagata. However, since March 2020, the B/Yamagata strain of influenza B virus has not been detected in circulation. This is believed to be partly due to public health measures put in place during the pandemic to limit the spread of Covid-19. Influenza B viruses are responsible for one in four flu infections each year.
Since the B-Yamagata strain no longer appears to pose a threat to public health, there is no need to include it in influenza vaccine formulations. The ETF recommends that this strain should ideally be removed from all live attenuated vaccines starting in the 2024/2025 season.To ensure vaccine supply for the next vaccination campaign, the transition Trivalent compositions for all other influenza vaccines should be completed by the 2025/2026 season.
Taking into account the ETF statement and the thoughts and advice of the WHO, the EMA Influenza Working Group has issued the following recommendations for this year’s strain.
Manufacturers of live attenuated or trivalent egg vaccines should include the following three strains for the 2024/2025 season: viruses similar to A/Victoria/4897/2022 (H1N1)pdm09; viruses similar to A/Thai/8/2022 (H3N2 ) and viruses similar to B/Austria/1359417/2021 (B/Victoria lineage).
Additionally, manufacturers of trivalent cellular vaccines should include the following three strains for the 2024/2025 season: viruses similar to A/Wisconsin/67/2022 (H1N1)pdm09; viruses similar to A/Massachusetts/18/2022 (H3N2) Viruses; viruses similar to B/Austria/1359417/2021 (B/Victoria lineage).
Inactivated vaccine manufacturers may consider producing a quadrivalent vaccine containing two influenza B strains for the 2024/2025 season. In this case, in addition to the above-mentioned strains, viruses similar to B/Phuket/3073/2013 (B/Yamagata lineage) are also considered suitable.
The EMA Committee for Human Medicinal Products (CHMP) approved the recommendations for the 2024/2025 influenza season at its March 2024 meeting.
The FDA recommends that marketing authorization holders submit applications to change the ingredients of centrally authorized seasonal influenza vaccines by June 17, 2024.