Equine H7N7 influenza A viruses are highly pathogenic in mice without adaptation: potential use as an animal model

Equine H7N7 influenza A viruses, representing a broad range of isolates, were lethal in mice without adaptation. After repeated passages, A/Equine/London/1416/73 acquired neurotropism upon intranasal infection. Thus, mice infected with equine influenza A viruses provide a model system for the study of highly virulent mammalian influenza viruses.