Officials said, however, that the vaccine will not be administered on a preventative basis because it is known to be effective up to four days after exposure and because in rare cases it can be deadly.
The administration has been in negotiations with pharmaceutical companies for weeks, and finally contracted with British firm Acambis Inc. and subcontractor Baxter International Inc. After diluting a current batch of 15.4 million doses, the country will have enough of the vaccine to give it to 286 million people.
Smallpox was declared eradicated from the globe in 1980 and has not occurred in the United States since 1949. But both the U.S. and the former Soviet Union had developed the virus to be used as a biological weapon and experts worry it could still be used in a terror attack.
“There’s been considerable discussion since September 11 about the possibility of smallpox being used as a weapon against Americans,” Health and Human Services Secretary Tommy Thompson told reporters today.
“We hope that increasing our smallpox vaccine stockpile would serve as a deterrent to any individual terrorist who would consider using smallpox as a weapon against us,” he said.
Scientists are hopeful that one dose of the vaccine could be divided into five doses, thus stretching the supply. The discovery could mean that the order would cost the administration $428 million instead of the previously budgeted $509 million. Researchers are now working to determine whether one dose can be diluted into ten.
The government had placed a previous order of 54 million vaccine doses with Acambis that will also be delivered next year.
Smallpox kills 30 percent of its victims and leaves others infected disfigured.
Routine smallpox vaccinations in the United States ended in 1972, and officials believe any administered before then would no longer be effective.