"The virus is now unstoppable. However, we do not expect to see a sudden and dramatic jump in the number of severe and fatal infections."
Cho said nearly 30,000 cases of swine flu, or H1N1 as it is being called, have been reported in 74 countries. Of those, 144 people died. Here in the United States, more than 13,000 cases have been reported, with 27 fatalities. Despite the numbers, Cho said the danger from the virus is "moderate." She stresses that most cases are mild and do not require treatment.
WHO will now ask drugmakers to speed up production of a swine flu vaccine, which is expected to be available after September. By moving to phase 6 -- the highest alert level -- governments will now be prompted to allocate more money towards containing the virus. Kathleen Sebelius, the U.S. Secretary of Health and Human Services, says the country is already gearing up:
"What this declaration does do is remind the world that flu viruses like H1N1 need to be taken seriously. We need to start preparing now in order to be ready for a possible H1N1 immunization campaign starting in late September."
There are some disturbing facts about this strain of flu. About half the people killed by swine flu were young and healthy. Usually, those people recover from the flu. And swine flu continues to spread as summer begins in the northern hemisphere. Flu traditionally disappears with the warm weather, but swine flu is bucking that trend.
Many are saying WHO's annoucement is several weeks too late. Chan said her experts admit there was a wider spread of the flu than what was being reported. And politics played a role -- last month, several countries urged WHO not to declare a pandemic, fearing social and economic upheaval. But with today's announcement, "This is WHO finally catching up with the facts," says flu expert Michael Osterholm of the University of Minnesota.
The last pandemic -- the Hong Kong flu of 1968 -- killed about a million people. Ordinary flu kills up to 500,000 people every year.