On Phillip Island off Australia's southeastern coast, wildlife teams have begun something the world has never seen before: a mass vaccination campaign against H5N1 avian influenza in a wild animal population. After the virus crossed into Australia for the first time in June and claimed its first penguin life within the island's 40,000-strong little penguin colony, authorities moved from vigilance to intervention. The effort asks not only whether a wild species can be protected through coordinated inoculation, but whether human ingenuity and care can outpace a virus already moving among the ver