The World Health Organization (WHO) has recently released its recommendations for the composition of influenza vaccines for the upcoming 2024-2025 northern hemisphere season. These recommendations were made after a 4-day meeting on the Composition of Influenza Virus Vaccines, where experts from WHO Collaborating Centres and WHO Essential Regulatory Laboratories analyzed influenza virus surveillance data.
Influenza, commonly known as the flu, is a highly contagious respiratory illness caused by influenza viruses. These viruses are constantly evolving, making it necessary to update the composition of influenza vaccines regularly to ensure their effectiveness. The WHO’s recommendations play a crucial role in guiding national vaccine regulatory agencies and pharmaceutical companies in developing, producing, and licensing influenza vaccines for the upcoming season.
For the trivalent vaccines, which protect against three strains of the influenza virus, the WHO recommends including an A/Victoria/4897/2022 (H1N1)pdm09-like virus, an A/Thailand/8/2022 (H3N2)-like virus, and a B/Austria/1359417/2021 (B/Victoria lineage)-like virus. These recommendations apply to both egg-based vaccines and cell culture- or recombinant-based vaccines.
In the case of quadrivalent vaccines, which protect against four strains of the influenza virus, the WHO advises including the B/Yamagata lineage component. Specifically, they recommend using a B/Phuket/3073/2013 (B/Yamagata lineage)-like virus. This recommendation applies to both egg- or cell culture-based vaccines and recombinant vaccines.
The WHO’s recommendations are based on extensive surveillance data collected by the WHO Global Influenza Surveillance and Response System (GISRS). This system monitors influenza activity worldwide and provides valuable insights into the circulating strains of the virus. By analyzing this data, experts can identify the most prevalent strains and make informed decisions about vaccine composition.
It is important to note that the recommendations issued by the WHO are not binding but serve as guidelines for vaccine manufacturers and regulatory agencies. Each country has its own regulatory processes and may choose to adopt the WHO’s recommendations or make adjustments based on their specific circumstances.
In conclusion, the WHO’s recent announcement of the recommendations for the influenza vaccine composition for the 2024-2025 northern hemisphere season is a crucial step in ensuring the effectiveness of influenza vaccines. By analyzing surveillance data and consulting with experts, the WHO provides guidance to vaccine manufacturers and regulatory agencies, helping them develop vaccines that target the most prevalent strains of the influenza virus. As we approach the upcoming flu season, it is essential for individuals to stay informed about the recommended vaccines and take proactive measures to protect themselves and their communities from the flu.
