EMA Recommends 3-Valent Influenza Vaccine for 2026/2027, Excluding 'Yamagata' Strain... Sanofi and GSK to Adjust Production
Official Transition to Excluding the Yamagata Strain and Implementing a 3-Valent Vaccine
The European Medicines Agency (EMA), through its Committee for Medicinal Products for Human Use (CHMP), has officially recommended the exclusion of the B/Yamagata strain from the 2026/2027 seasonal influenza vaccine and a transition to a 3-valent vaccine. The Yamagata strain has not been detected globally since March 2020, posing a low public health threat. This measure reflects the intention of health authorities to improve vaccine production efficiency by removing unnecessary antigens and to focus the immune response. This marks the end of the era of 4-valent vaccines, which have dominated the influenza market for several years, and is triggering adjustments to production lines across the industry.
Recommended Strains and Regulatory Timeline for the 2026/2027 Season
The influenza vaccine strains confirmed by the EMA for the 2026/2027 season will be applied in a dual manner, depending on the production method. For egg-based and live attenuated vaccine platforms, the recommended strains are A/Missouri/11/2025 (H1N1)pdm09-like virus, A/Darwin/1454/2025 (H3N2)-like virus, and B/Tokyo/EIS13-175/2025 (B/Victoria lineage)-like virus. For cell-based platforms, the A/H3N2 strain should be A/Darwin/1415/2025-like virus, and the B/Victoria strain should be B/Pennsylvania/14/2025-like virus. Companies holding marketing authorizations must submit variation applications to change the vaccine composition by June 15, 2026, making the timeline very tight.
Impact on Production Processes and Supply Chain Changes for Global Big Pharma
This recommendation requires direct changes to the production processes of leading influenza vaccine companies such as Sanofi (ticker: SNY), GlaxoSmithKline (GSK, ticker: GSK), CSL Seqirus, and AstraZeneca (ticker: AZN). Sanofi, which produces the egg-based 'VaxigripTetra,' and GSK, which produces 'Fluarix,' face the challenge of quickly transitioning to a 3-valent vaccine production system. CSL Seqirus, which has the cell-based 'Flucelvax,' must also focus on securing the recommended cell culture-specific strains and scaling up production capacity. AstraZeneca, which supplies the live attenuated vaccine spray 'FluMist,' must also rapidly introduce customized strains for the live attenuated vaccine platform.
Market Size Analysis and Profitability Prospects Following the Transition to 3-Valent Vaccines
The European influenza vaccine market is projected to grow from approximately $2.1 billion in 2025 to approximately $3.43 billion by 2033. The transition from 4-valent to 3-valent vaccines is expected to reduce production costs and improve margins for manufacturers by reducing the number of antigen raw materials produced in the production stage. However, the write-off of existing 4-valent vaccine inventory and regulatory compliance costs for the approval of new 3-valent vaccines will be short-term variables.
In the long term, the speed of technological transition from egg-based methods to cell-based and next-generation mRNA influenza vaccines will be a key competitive factor in determining companies' market share.
The European influenza vaccine market is approximately $2.1 billion in size as of 2025, and following this EMA recommendation, major manufacturers such as Sanofi (SNY), GSK (GSK), and CSL Seqirus must complete the transition to 3-valent vaccine production and obtain regulatory approval by June 15, 2026. From an investor perspective, the transition from 4-valent to 3-valent vaccines can contribute to short-term margin improvement by reducing costs, while the potential for asset impairment losses from existing 4-valent inventory should be monitored. For researchers and industry professionals, the rapid application of strains in cell-based and mRNA platforms compared to egg-based platforms will be a key indicator for securing market share in the future. In the medium to long term, clinical efficacy data for the new 3-valent formulation with the B/Yamagata variant excluded and changes in bidding prices in national immunization programs (NIP) will be decisive variables in determining companies' long-term profitability.