Decoding H5N1 adaptation in mammals for human infection potential
A new study investigates the human adaptive potential of the 2.3.4.4b H5N1 virus currently circulating in non-human mammals. The research focuses on understanding how this avian influenza virus has evolved in various mammalian hosts and its implications for potential human infections. By analyzing the sequences of viral proteins from infected non-human mammals - including dairy cattle, foxes, dolphins, and bears - the study assesses the presence of human-adapting mutations.
Certain non-human mammals, particularly foxes, dolphins, and bears, exhibit a higher potential for human adaptation due to specific mutations in viral proteins. The study highlights the acquisition of classical human-adapting mutations, such as those in the PB2 protein, which could facilitate human infections.
The 2.3.4.4b H5N1 virus has partially acquired classical human-adapting mutations, similar to those found in human influenza viruses such as H1N1pdm09 and seasonal H3N2. Notably, the Q591 adaptation in PB2 is emphasized as a significant mutation that enhances human adaptation.
The study raises concerns about the potential for spillover events from infected non-human mammals to humans, particularly given the increasing frequency of infections in dairy cattle.
