U.S. Buys $100 Million of Bird Flu Vaccine

WASHINGTON - The federal government has purchased $100 million worth of an experimental vaccine against the H5N1 bird flu strain, officials disclosed Friday — a down payment on a stockpile that health authorities concede would cover only a fraction of the country if the virus began spreading between people.

The vaccine, produced by a French manufacturer and still being tested, is intended to prime immune systems against a strain that has killed more than 60 people in Asia since 2003 — nearly all of them after close contact with infected poultry.

The H5N1 virus now circulates in birds across Vietnam, Thailand, Indonesia and beyond, and migratory flocks have carried it into Russia and Kazakhstan. The fear driving the stockpile is that the virus will mutate or swap genes with a human flu strain and become easily transmissible — the trigger for a pandemic.

"We are overdue," the nation's top flu official has said repeatedly. "It is not a question of if there will be another pandemic, but when."

The administration is drafting a national pandemic plan — expected within weeks — that officials say will cover vaccine production, antiviral stockpiles, hospital surge capacity and the quarantine powers the government would use in a worst case.

In the meantime, the United States is also buying millions of doses of the antiviral drug Tamiflu, the one medicine shown to blunt H5N1 in treated patients. The national stockpile of Tamiflu remains far below levels in Britain, Japan and other countries that ordered early; the drug's single manufacturer is racing to fill a global queue.

The vaccine purchase comes as flu-shot season opens with a fresh reminder of fragility: last year's season was upended when contamination shut down half the U.S. vaccine supply, and officials are still rebuilding the domestic production base.

Health experts caution that the experimental vaccine's protection against a future pandemic strain is uncertain — the virus would have mutated by definition — but say the stockpile lets factories practice making it at scale and may buy crucial time.