Research Priorities for Zoonotic and Pandemic Influenza Vaccines: Evidence and Recommendations from the WHO Public Health Research Agenda for Influenza (2024 Update).

Zoonotic influenza viruses, including highly pathogenic avian influenza and swine-origin variants, continue to cause sporadic human infections with, in some cases, high case fatality rates and potential for sustained human-to-human transmission. The COVID-19 pandemic underscored both the possibilities of rapid vaccine innovation and the persistent challenges in equitable access and public trust. This paper synthesizes the vaccine-related priorities from the 2024 update of the World Health Organization Public Health Research Agenda for Influenza, integrating evidence from systematic literature reviews commissioned, expert consultations, and analysis of lessons learned from recent health emergencies, to outline a research and policy roadmap for zoonotic and pandemic influenza vaccine preparedness. Key research priorities identified include development of broadly protective animal and human vaccines; improved understanding of correlates of protection; rapid and scalable manufacturing platforms; predictive modelling for strain selection; and targeted communication strategies to strengthen uptake. Experts have considered that implementing these priorities will require One Health integration, sustained investment, harmonized regulatory frameworks, and proactive community engagement to ensure that advances in vaccine science translate into timely, equitable public health protection.