Chiron Corp. expects to send the first 1.5 million doses of its Fluvirin vaccine to distributors early next week, said spokeswoman Alison Marquiss, and will continue shipping through early December. The company has said it plans to make 18 million to 26 million doses of vaccine for the USA this season.

British regulators suspended Chiron's license last year because of contamination problems at its England plant, causing a vaccine shortage in the USA. The British had restored Chiron's license this March, leaving FDA approval as the last hurdle before the company could send vaccine here.

Ample Supply

Wednesday's announcement means there likely will be 79 million to 97 million doses of flu vaccine available, easing concerns of a possible second season of supply problems. Sanofi Pasteur has said it will provide 50 million to 60 million doses of vaccine, and GlaxoSmithKline will make 8 million doses. MedImmune, which makes FluMist nasal spray vaccine, will make 3 million doses.

"Our anticipation is that we will have an ample supply of vaccine this year," said Lance Rodewald of the Centers for Disease Control and Prevention.

He said some doctors have reported delays in delivery, but FDA spokeswoman Julie Zawisza said via e-mail that vaccine production is "on track" and the spot shortages are "temporary."

Doctors usually start giving flu shots to patients in October, but this year, because of uncertainty about the size and timing of the vaccine supply, health officials recommended that only those at highest risk of serious illness be immunized before Oct. 24. Those groups include people 65 and older, residents of long-term-care facilities and children ages 6-23 months old.

"Optimal months for vaccination are October and November," Rodewald said, though "December is not too late, on up even until January."

Racing the Clock

But experience shows that vaccine delivered after November often goes to waste because consumers are no longer interested in getting immunized unless the flu season is particularly severe.

Chiron is racing the clock to get vaccine to distributors. "They've got until Thanksgiving or mid-November," says Wall Street analyst Geoffrey Porges of Sanford C. Bernstein.

Customers also are working against the clock. Yuan-Po Tu, who runs the flu vaccine program at the Everett Clinic in Everett, Wash., ordered flu shots from all three manufacturers, but so far only about 7,800 doses have arrived. The clinic orders up to 25,000 doses a year. He said he worries that Chiron's shipment may not arrive until December, which may be too late, leaving the clinic stuck with unused vaccine.