Scientists have made a groundbreaking discovery about the H5N1 avian influenza virus, which has been spreading in U.S. dairy cows. Researchers found that this highly pathogenic strain only needs one genetic mutation to bind effectively to human cells in the upper airway. This finding poses a significant threat for a new pandemic if the mutation becomes widespread.
The study revealed that avian influenza viruses have surface proteins allowing them to attach to bird cell receptors, which enables the virus to enter cells. However, the receptors in birds differ from those in humans by only a slight variation. The researchers found that switching receptor specificity from avian-type to human-type required only one genetic alteration.
This particular strain of H5N1 was first detected in North America in 2021 and has affected various animal populations, including wild birds, bears, foxes, and marine mammals. In the U.S., outbreaks have been linked to sick poultry or cows, with most human infections being mild cases among farmworkers at high risk of exposure. Notably, there have been no reported signs of transmission between people, as the virus’s receptor binding preference acts as a key barrier.
Source: https://www.scientificamerican.com/article/bird-flu-virus-is-one-mutation-away-from-adapting-to-human-cells