News Health & Medicine Cows might host both human and bird flus Molecules that allow entry to both kinds of influenza viruses have been found in cattle Cattle have entry portals that allow infection with both bird flu viruses (H5N1 avian influenza A, left) and human influenza viruses (H3N2 influenza A virus from a person, right). NIAID; Peter Cade/Getty Images; NIAID Share this:EmailFacebookTwitterPinterestPocketRedditPrint By Tina Hesman Saey May 14, 2024 at 9:15 am Cows have entry portals for both human and bird flus. This new finding may mean that cattle could host both types of flus at once.