New Recommendations for Vaccine Composition

The European Medicines Agency (EMA) has issued new guidelines for the composition of influenza vaccines for the 2024 season. These recommendations come in response to data from the World Health Organization (WHO) and are aimed at enhancing the effectiveness of seasonal flu vaccines.

Transition to Trivalent Vaccines

The EMA's Emergency Task Force (ETF) has proposed a significant shift from quadrivalent to trivalent vaccines, excluding the B/Yamagata component. This recommendation is based on the observation that the B/Yamagata strain has not been detected in circulation since March 2020, likely due to public health measures against COVID-19. Currently, quadrivalent vaccines protect against four main strains: A(H1N1)pdm09, A(H3N2), B/Victoria, and B/Yamagata. With the B/Yamagata strain no longer posing a public health threat, it is recommended for removal from live-attenuated vaccines starting in the 2024/2025 season, and from all other vaccines by the 2025/2026 season.

Specific Strain Recommendations

The EMA's ad hoc Influenza Working Group, taking into account the ETF's statement and WHO's guidance, has specified the following strains for the 2024/2025 season:

• Live-attenuated or egg-based trivalent vaccines should include:
  • A/Victoria/4897/2022 (H1N1)pdm09-like virus
  • A/Thailand/8/2022 (H3N2)-like virus
  • B/Austria/1359417/2021 (B/Victoria lineage)-like virus
• Cell-based trivalent vaccines should include:
  • A/Wisconsin/67/2022 (H1N1)pdm09-like virus
  • A/Massachusetts/18/2022 (H3N2)-like virus
  • B/Austria/1359417/2021 (B/Victoria lineage)-like virus

For inactivated vaccines, manufacturers are advised to consider producing a quadrivalent vaccine, which could include a B/Phuket/3073/2013 (B/Yamagata lineage)-like virus in addition to the recommended strains.

Endorsement and Application Deadline

The EMA's human medicines committee (CHMP) endorsed these recommendations during their meetings in March and May 2024. Given the continuous evolution of influenza viruses, updating vaccine strains is crucial for maintaining vaccine efficacy. Marketing authorisation holders are urged to submit applications to update the composition of centrally authorised seasonal influenza vaccines by June 17, 2024.

Highlights

• EMA recommends transitioning from quadrivalent to trivalent vaccines, excluding the B/Yamagata strain.
• Specific strains for 2024/2025 include A(H1N1)pdm09, A(H3N2), and B/Victoria lineage viruses.
• Quadrivalent vaccines may still include the B/Yamagata strain for the upcoming season.
• Recommendations are based on WHO data and endorsed by EMA's CHMP.
• Marketing authorisation holders should submit composition changes by June 17, 2024.

Data Source: 

https://www.ema.europa.eu/en/news/eu-recommendations-2024-2025-seasonal-flu-vaccine-composition

Replacement of quadrivalent seasonal influenza vaccines with trivalent vaccines in the EU. 

https://www.ema.europa.eu/en/documents/other/replacement-quadrivalent-seasonal-influenza-vaccines-trivalent-vaccines-eu_en.pdf

Amended EU recommendations for the seasonal influenza vaccine composition for the season 2024/2025.

https://www.ema.europa.eu/en/documents/regulatory-procedural-guideline/amended-eu-recommendations-seasonal-influenza-vaccine-composition-season-2024-2025_en.pdf