“There are hundreds of strains of bird flu, and most of them don’t infect humans, or even mammals,” Stephen Cusack told BioWorld. “There are two main reasons for that.” To be able to cause an infection, a virus “has to be able to get into the cell, and for that it needs a receptor,” Cusack said. For influenza viruses, those receptors are hemagglutinin receptors, and they differ in subtle but important ways between birds and mammals.
A whole genome sequencing study has been the first to demonstrate a strong association between infection with the avian influenza A virus H7N9 and rare, heterozygous single-nucleotide variants in the MX1 gene encoding for the myxovirus resistance protein A.
