Through a series of H9N2 viruses in birds and chickens, can lead to the production of a mutation that has a short stem NA can infect mice without the need for adaptation, and resulted in the selection of mutation PB2-E627K.
The H9N2 virus is a series of birds and poultry can lead to the production of a short stalk NA mutations that can infect mice without adaptation and resulted in the selection of mutant PB2-E627K.
The series of virus H9N2 as bird and chicken can lead to the production of mutation with a short stem NA that can infect mice without the first and result in the selection of the mutation. PB2-E627K.