Since first detected in 1996, the highly pathogenic H5N1 ‘bird influenza’ has been perennially widespread in wild birds and poultry worldwide. Outbreaks among cattle in the USA and recent infections in other mammals, both wild and domestic, have renewed public health concerns. Moreover, the 2024–2025 influenza season revealed 70 confirmed human H5N1 infections in the USA alone. If another mutation enables H5N1 transmission between humans, severe consequences could result.

Existing vaccine candidates, of which many governments maintain a small stockpile, may offer some protection against infection and serious illness. Promising research to develop a more effective and easier-to-manufacture mRNA vaccine1 has been stalled, as the American Department of Health and Human Services recently cancelled over $700?million in contracts with Moderna. If a human outbreak of bird influenza occurs, this setback will delay vaccine development and production by months or years and will prolong vaccination shortages worldwide. In addition, antiviral treatments and other pandemic countermeasures would be in shortage, necessitating frameworks for fair allocation.