Influenza virus is an infectious agent belonging to the virus family Orthomyxoviridae that causes a respiratory tract infection (influenza or 'flu') in vertebrates. There are three main species, and ...

Nov. 28, 2025 Researchers discovered why bird flu can survive temperatures that stop human flu in its tracks. A key gene, PB1, gives avian viruses the ability to replicate even at fever-level heat.