Updated

Federal health officials announced Thursday evening that the maker of a nasal flu vaccine (search) will provide one million additional doses than expected to the U.S. market this fall.

Officials from MedImmune (search), which makes the nasal flu vaccine FluMist (search), say the company agreed to produce the extra vaccine to help shore up supplies following the loss of nearly half of the U.S. vaccine supply in early October.

FluMist goes for between $16 and $23.50 per dose but is not a replacement for injectable flu shots in most cases. FluMist is approved only for healthy persons 5 to 49 years old, meaning that it can't be used by elderly persons and most others considered at high risk this flu season.

Officials say they hope that healthy persons who could spread flu to at-risk persons, such as health workers and household contacts of infants under six months, will use FluMist.

"This is for people that are healthy, people that should not be getting the injectable vaccine," Health and Human Services Secretary Tommy G. Thompson says.

MedImmune president David Mott says the company plans to turn out about 400,000 new does per week and that the company will eventually produce about 3 million FluMist units.

Vaccine maker Chiron Corp. announced Oct. 5 that British regulators had barred it from shipping 46 million to 48 million injectable vaccine doses to the U.S. because of contamination at a plant in Liverpool, England. The loss of nearly half of the U.S. supply sent American officials scrambling for extra doses and touched off a political firestorm in the presidential election campaign.

Bush administration officials now say they have secured some 61 million total doses for the 2004-2005 flu season, about the same total number used in 2003. But updated vaccination guidelines from the CDC place nearly 100 million elderly and ill Americans and infants in the group urged to get shots.

FDA Acting Commissioner Lester Crawford says the agency is in negotiation with authorities from Canada and a host of European countries to try to secure an estimated 5 million outstanding doses currently unclaimed on the world market.

"Wherever there is flu vaccine, we are in negotiation, including France," he says.

Emergency vaccines would be brought into the U.S. under "some sort of abbreviated approval" that would place them under the regulatory control of the FDA, Crawford says.

Meanwhile, Thompson repeated his call for high-risk persons to avoid standing in lines for flu vaccine and to "be persistent" if they find no vaccine available at their usual outlet.

"Just because you're doctor does not have the vaccine today does not mean that he or she or that clinic will not have it in another week," he says.

Also Thursday, nine Senate Democrats called for a government investigation into when FDA officials first knew of the impending vaccine shortage and if they acted properly to prevent it.

"I think it's extremely important that we find out why and how this happened," Senate Minority Leader Tom Daschle, D-S.D., said in a statement. "The shortage of flu vaccine is a national crisis and lives are at stake. We need to know how FDA handled this case from the beginning so that we can make sure it never happens again."

By Todd Zwillich, reviewed by Charlotte Grayson, MD

SOURCES: David Mott, president, MedImmune. Tommy G. Thompson, secretary, Department of Health and Human Services. Lester B. Crawford, acting commissioner, FDA. Sen. Thomas A. Daschle (D-S.D.), Senate minority leader.