An increase above level 3 on the WHO’s six-step alert system would be the first since the United Nations agency began grading pandemic risks in 1999. The agency’s guidelines say the goal of a level 4 alert is “containment of the new virus within a limited area or delay of its spread,” suggesting the change will trigger travel warnings. Level 5 would be “a strong signal that a pandemic is imminent.”
The WHO may advise governments to screen people coming in and out of Mexico and other affected areas, limit travel, distribute antiviral medicines from global stockpiles and start the process of producing a pandemic vaccine, according to the guidelines revised last month. The people familiar with the WHO declined to be named because the deliberations are confidential. Gregory Hartl, a spokesman for the WHO, declined to comment.
Swine flu’s spread in Mexico, the U.S. and Canada is heightening concern that the virus may spark the world’s first influenza pandemic since the 1968 Hong Kong flu, which killed as many as 4 million people.
“The tenor at the moment is they should call it a pandemic,” said John Oxford, a virologist at Retroscreen Virology Ltd. in London who’s not involved in the discussions. “We’ve seen how it’s moving.”
Australia, Japan, Singapore and South Korea are among countries screening travelers for fever, while Hong Kong raised its swine-flu response level to “serious” from “alert.” The European Union advised travelers to avoid areas affected by the outbreak. The U.S. declared swine flu, normally spread among pigs, a public health emergency after 20 people contracted the disease.