Flu viruses that can use a second cellular entry point may move more effectively between animals and humans, scientists say.

The flu virus is changing in ways never seen before, ... Scientists attribute this spike to influenza A’s newly observed ability to modify its structure in response to environmental conditions, ...

Flu viruses package essential functions into a small integral membrane protein known as M2. ... T. Flu BM2 structure and function. Nat Struct Mol Biol 16, 1207–1209 (2009) . https://doi ...

California researchers say the world may be just one genetic tweak away from human-to-human transmission of the H5N1 bird flu virus — a worrisome mutation that could open the door to widespread ...

Two types of influenza viruses are responsible for seasonal flu outbreaks: Influenza A and B. Influenza A accounts for around 75 percent of all cases and tends to cause more severe illness in adults.

All four flu pandemics — in 1918, 1957 and 1968 and the swine flu pandemic of 2009 — were caused by Type A viruses. Influenza B viruses, however, only circulate in humans.

No human cases have been reported in New York, but the avian virus was very common among certain wild birds on Long Island in 2022 and 2023. ... The flu virus has also been found in mammals.