#Genetic and #antigenic characteristics of #zoonotic #influenza A viruses and development of candidate #vaccine viruses for pandemic preparedness (#WHO, Oct. 31 '25)
September 2025 The development of influenza candidate vaccine viruses (CVVs), coordinated by WHO, remains an essential component of the overall global strategy for influenza pandemic preparedness . Selection and development of CVVs are the first steps towards timely vaccine production and do not imply a recommendation for initiating manufacture . National authorities may consider the use of one or more of these CVVs for pilot lot vaccine production , clinical trials and other pandemic preparedness purposes based on their assessment of public health risk and need. Zoonotic influenza viruses continue to be identified and evolve both antigenically and genetically, leading to the need for additional CVVs for pandemic preparedness purposes. Changes in the antigenic and genetic characteristics of these viruses relative to existing CVVs and their potential risks to public health justify the need to develop new CVVs. This document summarizes the antigenic and genetic c...