The supplier of half the country's influenza vaccine stunned public health officials yesterday by announcing it would provide no doses this year, prompting immediate fears of a shortage and a scramble to ration the available shots - just weeks before the flu season begins.
Chiron Corp. will provide none of the 46 million to 48 million doses it had expected to ship this month to the United States; a British regulatory agency unexpectedly yanked the company's production license and blocked it from releasing the vaccine.
"This is very disappointing news that creates a serious challenge to our vaccine supply for the upcoming flu season," U.S. Secretary of Health and Human Services Tommy G. Thompson said in an afternoon conference call with reporters.
The loss of half the country's flu vaccine supply - at a moment's notice - resulted in an immediate change in federal recommendations on immunization that hinges on voluntary rationing.
With the vaccine in short supply, health officials said, it should first go to people at highest risk of complications from the flu: those 65 and older; those with chronic health conditions such as kidney disease or AIDS; pregnant women; children 6 months to 23 months old; and health care workers.
Healthy people should skip flu shots unless more doses become available, officials said.
Triage for shots
"Our immediate focus will be on making sure that the supply of vaccine that we do have reaches those who are the most vulnerable," said Thompson.
Still, depending on the severity of this year's flu season, the estimated 56 million doses that are available might not be enough to cover everyone who most needs protection.
"The one thing you can be certain with influenza is that you can't really predict what's going to happen," said Dr. Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases. With the available vaccine supply, he said: "I think we'll at least come close."
There will be adequate doses for children younger than 2, because they are being supplied by the other major manufacturer, Aventis Pasteur.
California-based Chiron, which produces the Fluvirin vaccine at a plant in England, announced in August that it was delaying its vaccine shipment to the United States after several batches were found to be tainted.
