It's official, the swine flu has been upgraded to pandemic.
WHO chief Dr. Margaret Chan made the announcement Thursday after the U.N. agency held an emergency meeting with flu experts. Chan said she was moving the world to phase 6 — the agency's highest alert level — which means a pandemic, or global epidemic, is under way.
"The world is moving into the early days of its first influenza pandemic in the 21st century," Chan told reporters. "The (swine flu) virus is now unstoppable."
The last pandemic — the Hong Kong flu of 1968 — killed about 1 million people. Ordinary flu kills about 250,000 to 500,000 people each year.