Researchers have identified new roles for a protein long known to protect against severe flu infection -- among them, raising the minimum number of viral particles needed to cause sickness.
A Canadian teen who is in critical condition after contracting H5N1 bird flu was infected with a version of the virus that is different from the one circulating in U.S. cattle.
There are other types of flu that primarily infect animals, like bird flu and now swine flu. The real name for swine flu is H1N1 flu. It is called swine flu because a virus that causes ...