The Swine Flu Now at Pandemic Alert Phase 5. What Does that Mean
Pandemic Alert Phases
In nature, influenza viruses circulate continuously among animals. Even though such viruses might theoretically develop into pandemic viruses, in
Phase 1 no viruses circulating among animals have been reported to cause infections in humans.
In Phase 2 an animal influenza virus circulating among domesticated or wild animals is known to have caused infection in humans, [...]
