A Bird-Flu Pandemic in People? Here’s What It Might Look Like.

Crucially, no forms of the bird flu virus seem to have spread efficiently from person to person. That is no guarantee that H5N1 will not acquire that ability, said Yoshihiro Kawaoka, a virologist and bird flu expert at the University of Wisconsin-Madison.“ I think the virus is clearly changing its property, because we never saw outbreaks in cows,” Dr. Kawaoka said.