EU Recommendations for 2026/2027 Seasonal Flu Vaccine Composition

The European Medicines Agency (EMA) has released its recommendations for the strains that should be included in seasonal influenza vaccines for the 2026/2027 flu season. This announcement aims to enhance vaccine effectiveness in response to evolving influenza viruses.

Based on data from the World Health Organization, the EMA suggests that manufacturers of both egg-derived and live-attenuated vaccines include specific virus strains for the upcoming season. Notably, the vaccine formulation will not contain the B/Yamagata strain, which hasn’t been prevalent since March 2020.

Historically, influenza vaccines included four main strains to protect against seasonal flu, but the absence of B/Yamagata has led to its exclusion from the upcoming formulation. This change aligns with WHO recommendations regarding the composition of the vaccines for the same period.

In cases where quadrivalent vaccines are still required—especially in regions that have not transitioned to trivalent vaccines—it is suggested that manufacturers use a B/Yamagata lineage strain from previous years as a reference.

The recommendations were endorsed during the EMA's human medicines committee meeting in March 2026, reinforcing the necessity for vaccine manufacturers to adapt to the continuous evolution of influenza viruses.

The EMA has advised marketing authorization holders to submit applications to update vaccine compositions by 15 June 2026, ensuring timely preparation for the upcoming season.

These proactive measures underscore the importance of flexibility in vaccine development to maintain public health effectiveness against seasonal influenza, reflecting the dynamic nature of viral pathogens.