Virtual meeting on Wednesday, 19 March 2025 from 13:00 to 19:15 CET (Geneva time)
BACKGROUND
H5N1 is one of several influenza viruses that causes a highly infectious respiratory disease in birds called avian influenza (or "bird flu"). Infections in mammals, including humans, have also been documented.
H5N1 influenza virus infection can cause a range of diseases in humans, from mild to severe and in some cases, it can even be fatal. Symptoms reported have primarily been respiratory, but conjunctivitis and other non-respiratory symptoms have also been reported. There have also been a few detections of A(H5N1) virus in persons who were exposed to infected animals or their environments but who did not show any symptoms.
The goose/Guangdong-lineage of H5N1 avian influenza viruses first emerged in 1996 and has been causing outbreaks in birds since then. Since 2020, a variant of these viruses has led to an unprecedented number of deaths in wild birds and poultry in many countries. First affecting Africa, Asia and Europe, in 2021, the virus spread to North America, and in 2022, to Central and South America. From 2021 to 2022, Europe and North America observed their largest and most extended epidemic of avian influenza with unusual persistence of the virus in wild bird populations.
Since 2022, there have been increasing reports of deadly outbreaks among mammals also caused by influenza A(H5) – including influenza A(H5N1) – viruses. There are likely to be more outbreaks that have not been detected or reported. Both land and sea mammals have been affected, including outbreaks in farmed fur animals, seals, sea lions, and detections in other wild and domestic animals such as foxes, bears, otters, raccoons, cats, dogs, cows, goats and others.
WHO works with countries to help them prevent, detect and manage cases of H5N1 virus infection in humans when they occur. WHO collaborates with global health partners and agencies, including the World Organization for Animal Health (WOAH), and the Food and Agriculture Organization of the United Nations (FAO), to monitor the risk, and control and prevent the spread of animal diseases.
WHO’s global laboratory system, the Global Influenza Surveillance and Response System (GISRS), identifies and monitors strains of circulating influenza viruses, and provides advice to countries on their risk to human health and available treatment or control measures. WHO works with partners around the world on pandemic preparedness for H5N1 and other animal influenzas.
Influenza H5 pathogens have been included in the list of priority pathogens by the WHO R&D Blueprint for Epidemics1. To coordinate efforts for research preparedness of H5N1 outbreaks, this global consultation will review current and novel vaccines and preventive pharmaceuticals.
OBJECTIVES
The objectives of this meeting are to:
- Identify the knowledge gaps and priority research questions related to the development and evaluation of medical countermeasures to prepare for and respond to H5N1 outbreaks
- Outline regulatory pathways for mRNA vaccines and other novel approaches
- Review other therapeutics, including monoclonal antibodies and long-acting antivirals
EXPECTED OUTCOMES
- Outline a roadmap for research and development
- Promote international collaboration among various researchers and research institutions
PRESENTATIONS
Introduction pathogen prioritization - orthomyxovirus working group
A viral family approach to the Orthomyxoviridae family
Current state of H5N1 mutations
What have we learned about virus distributions from monitoring mutations?
Relationship between mutations and pathogenicity
Overview of H5N1 vaccines
Licensed and stockpiled vaccines
Influenza vaccines: safety considerations
What animal vaccines exist or are under development, and what could be their potential role?
Estimated impact of mitigation measures: overview of mathematical modelling consultation
Pathway for novel vaccines (and strain changes) evaluation
Coverage of emerging strains by available vaccines
Critical research needs on animal models
Critical research needs on assays
Evaluation of the immune response after vaccination
Regulatory considerations for the evaluation of a new H5N1 candidate vaccine including mRNA
Avian and pandemic influenza vaccines and influenza antivirals
Overview of investigational products including broad protection
Developer’s Corner (Kelly Lindert, Pfizer)
Developer’s Corner (Brett Leav, Moderna)
Developer’s Corner (Robert Walker, Novavax)
Other pharmaceuticals as preventive tools
Summary of the meeting, next steps
RECORDINGS (Interpretation available in all UN language)
Recording of the meeting - Part 1
Recording of the meeting - Part 2