Highly pathogenic avian influenza (HPAI) viruses cross species barriers and have the potential to cause pandemics.

The adaptability is a key factor in AIV to infect multiple non-avian species, including humans, companion animals, aquatic mammals, carnivores, and other mammals.

The aim of such an agreement is to enhance global preparedness for future COVID-19-like pandemics and mitigate the risk of similar catastrophic consequences.

Infection of highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b in dairy cows causes severe mastitis and milk production losses.

On 2 April 2025, the International Health Regulations (IHR) National Focal Point (NFP) for Mexico notified WHO of the country’s first laboratory-confirmed human infection with an avian influenza A(H5N1) virus in the state of Durango.

At the present time, based on available information, FAO-WHO-WOAH assess the global public health risk of influenza A(H5) viruses to be low.

The receptor-binding preference of haemagglutinin of influenza A viruses (IAVs) is a major determinant of host range, and avian viruses preferentially bind α2,3-linked sialic acids, whereas human IAVs recognize α2,6-linked sialic acids.

Highly pathogenic H5N1 avian influenza viruses started circulating in lactating dairy cattle in the USA at the end of 2023 and these viruses are now rapidly spreading between cows.