A new three-year international research project has been launched to address the escalating global threat posed by Highly Pathogenic Avian Influenza A viruses (HPAIV).
Focused on the H5 subtype, the project, Comprehensive Analysis of Transmission, Tropism, and Livestock Epidemiology of Avian Influenza Viruses, is funded through the EU Partnership on Animal Health and Welfare (EUPAHW). Led by the University of Copenhagen, it brings together four leading European partners, including The Pirbright Institute.
Since 2022, H5 HPAIVs have become panzootic, dramatically expanding their geographic reach and host range. Responsible for widespread outbreaks in wild birds and poultry, the viruses cause mass mortality, severe economic losses, and increased concern over spillover into mammalian species - including livestock and potentially humans.
Professor Ian Brown OBE, Project Lead and Group Leader in Avian Virology at The Pirbright Institute, said:
“We are pleased to announce the launch of this important new project. Current threat levels from H5 avian influenza viruses in the UK and Europe are high, and the possibility of spread to livestock species such as dairy cattle and pigs cannot be excluded. Our work will focus on evaluating vaccination strategies as emergency interventions and assessing immune responses to inform the future use of available vaccines.”
Infections in mammals are of particular concern, as each spillover event provides opportunities for viral adaptation, potentially increasing zoonotic risk. The list of mammalian hosts infected with HPAIV continues to grow, with suspected cases of mammal-to-mammal transmission reported. Recent H5 outbreaks in United States dairy cattle have highlighted new reservoirs in livestock populations.
The project brings together Professor Lars Erik Larsen, University of Copenhagen; Drs Laurence Finot and Delphine Payros, INRAE – the National Research Institute for Agriculture, Food and Environment, France and Professor Dr Martin Schwemmle, from the University of Freiburg, Germany.
Professor Larsen said:
“Each of us brings specialist research skills to this EUPAHW project. I lead a research group focused on viral dynamics in production animals, wildlife, and companion animals, bridging molecular research with field impact. We have produced significant work in diagnostics, vaccine innovation, and understanding virus transmission, including insights into H5N1 avian flu in cows.”
The project is structured around three interconnected work packages:
I. Viral Genetics and Molecular Characterisation
Researchers will analyse H5 HPAIV in molecular detail using in vitro assays to identify key genetic markers, validated and further studied using reverse genetics.
II. Mammalian Host Susceptibility
Focusing on cattle and pigs, this work package investigates viral replication sites, including mammary glands of lactating cows. Advanced histopathology and transcriptomic approaches will be applied to infected tissues and mammary gland organoids.
III. Immune Responses and Vaccination Strategies
This package examines antibody-mediated immune responses in livestock and assesses innovative vaccination platforms, including mRNA, viral vectors, and subunit vaccines. All approaches will be compatible with DIVA (Differentiating Infected from Vaccinated Animals) strategies and will consider multiple H5 antigens to enhance broad, cross-species protection.
Researchers will also explore different routes of immunisation to optimise protective immune responses in cattle udders and pig respiratory systems, using state-of-the-art immunological tools. Extensive analysis of both systemic and local immune responses will be led by a multidisciplinary expert team, including specialists in cattle and swine immunology and vaccine escape mechanisms.
More information about Pirbright’s work on Avian Influenza is available on our website.