Progress on viral and host determinants of influenza A virus species specificity

Influenza A viruses have a wide range of hosts and are highly infectious, which can cause zoonotic diseases and pose a serious public health threat to human safety. An influenza pandemic could outbreak if new strains gain the ability of human-to-human transmission, either by genetic mutation or by gene reassortment. It is an urgent issue for the scientific community to reveal the genetic basis and molecular mechanisms underlying the interspecies transmission of influenza viruses, which will provide important implications for the effective monitoring and prevention of potential influenza pandemics. In this review, we summarize the molecular determinants of influenza viruses for host adaptation, and highlight the advances in the gene mutations of the virus itself and the interaction between virus and host factors. This will help to make a theoretical reserve for the next influenza pandemic and find new strategies to fight against influenza.