System bracing for future flu shot shake-up

While public health officials, physicians and other health care professionals are struggling with one of the most difficult flu vaccine supply situations in years, plans are also in the works for the possibility that next season might not get much better.

"On Oct. 5, we recognized that our strategic outlook had to take into consideration the possibility that there could be no Chiron vaccine next year," said Centers for Disease Control and Prevention Director Julie Gerberding, MD, MPH.

That was the day the Medicines and Healthcare Products Regulatory Agency, the Food and Drug Administration's British equivalent, suspended Chiron Corp.'s license to manufacture influenza vaccine because of contamination problems. Instantly, the 46 million to 48 million doses promised to the United States were put on hold, nearly halving the total expected supply.

Chiron submitted to the FDA in November 2004 a remediation plan and has made clear its intent to be back in the flu vaccine business for the 2005 season.

"We are committed to taking all necessary actions to ensure an adequate vaccine supply for the 2005-06 influenza season," said Howard Pien, Chiron's president and CEO, in a statement on the firm's Web site.

Still, although nobody doubts that Chiron's efforts are sincere, many experts are less than sure that the company can resolve its difficulties as soon as this spring, when the vaccine production cycle begins again.

"Most of us are pessimistic," said William Schaffner, MD, who serves as chair of the Dept. of Preventive Medicine at Vanderbilt University Medical Center in Nashville, Tenn.

If Chiron is not able to return to the market, experts believe that several scenarios could play out.

The United States could continue to have limited supplies, as is currently the case, but would not be caught off guard. If this were to happen, MedImmune, the company that makes the nasal version, and Aventis Pasteur, the other manufacturer of injectable vaccine, would have more advance notice to compensate for the shortfall. Still, it's unlikely that these efforts would lead to a total supply reaching the nearly 100 million doses that were anticipated this season.

"Aventis Pasteur is committed to producing as much influenza vaccine as seems prudent, depending on availability of vaccine from other manufacturers and on market demand," said Aventis spokesman Len Lavenda. "We are now preparing for 2005 and assessing the potential for increasing our production."

Also under this scenario, public health officials and physicians would be able to use one consistent message throughout the season. There would not be the need to switch midstream from having an ample flu shot supply and trying to convince as many people as possible to take advantage of it to unexpectedly facing diminished resources and trying to reserve vaccine for those at highest risk.

Government health agencies also would have more time to scare up supplies from manufacturers that don't usually serve the U.S. market.

"If the worst case happens and we don't have the Chiron vaccine, we'll be working with the other international suppliers to try to get licensure of their product. We'll be working with domestic suppliers to see what, if anything, we as a government can do to scale up their production," Dr. Gerberding said. "And we'll be planning on our immunization programs to take under consideration whatever contingencies are necessary to meet the demands of the high-priority populations."

Market changes?

Alternate circumstances also could play out. For instance, the supply chain could be reinvigorated by the entry of other manufacturers into the U.S. marketplace.

ID Biomedical, a Canadian company, has announced its intent to roll up its sleeves to the tune of 38 million doses by 2007 -- although it could start delivering some supplies earlier depending on regulatory approval.

GlaxoSmithKline, which supplied at least 1 million doses this season under an Investigational New Drug application, also plans to apply for the FDA stamp of approval in the first half of 2005. The company hopes to be able to supply 10 million to 20 million doses of approved vaccine this year.

"That provides some hope that we'll have a more stable supply of flu vaccine for 2005," said AMA Trustee Ronald Davis, MD.

Solvay Pharmaceuticals, which manufactures the traditional egg-based vaccine available in Europe, is building a factory that would manufacture a cell-based version that could, years down the road, end up in the United States.

There is growing sentiment, however, that the government needs to be more involved. Also, some say the root of the problem has nothing to do with the number of manufacturers and more to do with the fact that relying on the free market always will tempt chaos.

"Leaving the flu vaccine supply totally dependent upon just the free market is fraught with problems," said Mike Crutcher, MD, MPH, commissioner of health at the Oklahoma Dept. of Health. "There's going to have to be some government involvement in securing the flu vaccine supply."

But whatever surprises the next flu season might deliver, concern about the current season continues. As of the beginning of January, the flu season had been mild, but so was vaccine demand. There might have been less vaccine this season, but there is also evidence that more could be left in some areas than ever before. To cut the chance that these supplies might not be used -- despite shortfalls in some areas -- the CDC's Advisory Committee on Immunization Practices expanded its list of those recommended to get the vaccine. The expansion is recommended only for those regions with ample amounts on hand.

This situation might be the result of an early October 2004 plea asking some people to forgo the shot so that those who needed it more could get it. Physicians report that some of their high-risk patients stepped aside, thinking that their shots would go to those in more need. "That is not what we want [high-risk people] to be doing," Dr. Gerberding said.

Also, according to a report in the CDC's Morbidity and Mortality Weekly Report published Dec. 17, 2004, more than half of those recommended to receive the shot did not even try to get it. A third said this was because they either believed there was no vaccine available or they wanted to wait until more was available.

The National Influenza Vaccine Summit organized by the American Medical Association and the CDC will meet in early May to discuss these issues.