WHO: Swine Flu Now A Pandemic, 1st In 41 Years

He said the "soft buildup" to declaring swine flu a pandemic has been helpful.

"That allows people to get used to what is otherwise a scary word, understand the particulars of the disease, and that should mean reaction will be a little more information-based and a little less emotional," Ropeik said in an e-mail.

WHO will now recommend that pharmaceutical companies make swine flu vaccine. The agency typically recommends which flu strains drug companies should use in the vaccines. In a global outbreak, WHO also advises whether companies should make pandemic vaccine.

The decision to make pandemic vaccine is a gamble. Most flu vaccine makers cannot make both regular seasonal flu vaccine and pandemic vaccine at the same time. That means they must decide which one the world will need more.

Drug giant GlaxoSmithKline PLC said it could start commercial production of pandemic vaccine in July but that it would take months before large quantities are available.

Glaxo spokesman Stephen Rea said the company's first doses of vaccine would be reserved for countries who had ordered it in advance, including Belgium, Britain and France. He said Glaxo would also donate 50 million doses to WHO for poor countries.