Swine flu is more dangerous than regular flu and could cause an especially deadly flu season in the United States this winter, UW-Madison research suggests.
The swine flu virus, also known as H1N1, infects cells deep in the lungs of animals, a study by campus virologist Yoshihiro Kawaoka found. That could explain why swine flu has caused serious cases of viral pneumonia in healthy people, something normal flu generally doesnâ??t do, he said.
Another worrisome finding: Only the very elderly â?? people born before 1918 â?? appear to have any natural protection to the new virus, Kawaoka said. Previous reports have suggested that the immune systems of people older than 60 could help ward off swine flu.