H5N1 strain in cattle “does not pose a major threat to humans”

A panzootic outbreak of the highly pathogenic avian influenza virus H5N1 has spread to several continents and has been detected in milk samples from dairy cattle in the United States, spreading to 891 farms across sixteen states. The virus is primarily transmitted through milking and contaminated equipment. However, it is not a major threat to humans. Researchers at the Pirbright Institute have found that the viruses tested bind exclusively to avian-like receptors and have a high membrane fusion pH, suggesting that they are unlikely to transmit efficiently between humans. The authors emphasize the importance of continued surveillance and risk assessment to mitigate the impact of the virus on public health and agriculture.

The highly pathogenic avian influenza virus (HPAIV) H5N1 has caused a panzootic outbreak affecting all continents except Australia, expanding its host range to several mammalian species. In March 2024, the H5N1 virus clade 2.3.4.4b was first detected in milk samples collected from dairy cattle in Kansas and Texas in the United States. Since then, it has been re-detected in cattle on 891 farms in sixteen states across the country. In this regard, the strain is thought to be predominantly transmitted through milking and the movement of infected animals or contaminated equipment between farms or states. The H5N1 strain does not pose a major threat to humans In this context, researchers at the Pirbright Institute have compared the H5N1 viruses from cattle and goats with the dominant avian strain in the United Kingdom. Focusing on receptor binding, fusion pH and thermostability, the scientists found that all H5N1 viruses tested showed binding exclusively to avian-like receptors. In the ...