New Study Shows H5N1 Virus Adapting to Mammals in Unprecedented Ways

A recent study has revealed that highly pathogenic H5N1 avian influenza viruses are evolving to adapt to mammals in ways that could have serious implications for humans, wildlife, and livestock worldwide. The study, conducted during a massive outbreak among elephant seals in Argentina in 2023, demonstrated clear evidence of mammal-to-mammal transmission of the virus on a global scale.

The genomic analysis of the outbreak showed that the H5N1 virus is now evolving into separate avian and marine mammal clades in South America, a phenomenon that has never been observed before. Researchers are concerned that these adaptations could potentially lead to the virus jumping to other species, including humans.

The outbreak began in 2020 with the emergence of the current variant of H5N1 clade, which caused widespread deaths among seabirds in Europe before spreading to South Africa, the U.S., and Canada. By February 2023, the virus was detected in Argentina for the first time, affecting poultry initially before making its way to marine mammals, resulting in unprecedented mass mortality among elephant seals.

The study’s co-authors emphasized the importance of continued monitoring and investigation to fully understand the implications of the virus for human health, wildlife conservation, and ecology. The research was funded by the Wildlife Conservation Society, UC Davis, and the National Institute of Agricultural Technology.