Mercury-free flu shot supply running short

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www.mercurynews.com/mld/mercurynews/news/10068383.htm
San Jose Mercury News (subscription), CA
Posted on Mon, Nov. 01, 2004

DEARTH OF VACCINES FOR INFANTS AS EXPERTS URGE USE FOR 1ST TIME
By Julie Sevrens Lyons
Mercury News

There's another flu vaccine shortage, one you haven't heard of: the lack of mercury-free shots for infants.

In response to fears that mercury in vaccines could be harmful to children, federal health authorities have had the element removed from every routine immunization for infants -- except the flu shot.

For several years, one vaccine manufacturer, Aventis Pasteur, has been producing a pediatric influenza vaccine that does not contain thimerosal, a preservative that contains mercury.

``The problem is, there isn't enough thimerosal-free influenza vaccine to go around,'' said Dr. Julia McMillan, a professor of pediatrics at Johns Hopkins University, and a member of the American Academy of Pediatrics committee on infectious diseases.

It is a phenomenon that is causing headaches for some parents and pediatricians this fall, the first time that health agencies have recommended babies 6 to 23 months old get the inoculation.

The shortage -- which is not linked to the production problems behind the dearth of adult flu shots -- does not concern many health officials, however, who point out that scientific studies have largely refuted suggestions that thimerosal is behind the country's record rates of autism and other neurological disorders.

Regular shots urged

Health authorities knew there would not be enough mercury-free influenza vaccine to meet the increased demand for childhood vaccination this year, but recommended that infants get flu shots anyway.

An influenza vaccine with some mercury, they reasoned, is still better for children than the flu, which has resulted in hospitalization rates of toddlers comparable to those of frail seniors. Last influenza season, the flu killed more than 150 children nationwide.

But nervous parents who would prefer that their children get a mercury-free flu shot have been disheartened to learn the vaccine is not always available in the Bay Area. Many pediatricians won't advertise that they have the sought-after mercury-free doses, and will not offer them to children unless parents specifically request it, the Mercury News has found.

The American Academy of Pediatrics says the supply is likely to be insufficient ``for the next several years.''

The recommendation to immunize infants against influenza creates a potential increase in demand for flu shots of more than 12 million doses per year, according to the academy. And yet just 4.6 million doses of the vaccine have been made without thimerosal this year.

``I think our officials did not do their job in getting the safest vaccines for our population,'' said Sallie Bernard, executive director of SafeMinds, a non-profit group looking into the role of mercury in the development of neurological disorders. ``Right now it's an unfortunate situation because parents are put in this difficult position of having to choose'' between forgoing a flu shot for their kids and exposing them to mercury.

Costly process

Making mercury-free vaccines is difficult and costly, requiring that thimerosal be extracted from traditional flu shots. The process results in the loss of one-third of the original volume of the flu vaccine.

Such a prospect is particularly troubling, given the already dire shortage of the vaccine, said Dr. Randy Bergen, a pediatric infectious disease specialist at Kaiser Permanente in Walnut Creek.

``In a year like this, that can be catastrophic,'' Bergen said.

And yet Bergen said he recognizes how fearful some parents are that thimerosal may be linked to autism, even though major research studies, including a sweeping Institute of Medicine report released this year, have concluded that the preservative is not harmful to children's health.

Thimerosal has been used in vaccines since the 1930s to help prevent bacteria and fungus from contaminating the doses. It is made up of 50 percent mercury by weight, and is metabolized in the body into ethylmercury, which differs from methylmercury -- the toxin found in air pollution and contaminated fish.

In the 1990s, infants were exposed to as much as 187.5 micrograms of thimerosal from routine immunizations. That coincided with a nationwide surge in autism rates in children, making some parents and pediatricians concerned that the vaccines could somehow be to blame.

In 1999, the government began to phase out thimerosal in childhood vaccines, and by 2003, infants under 6 months who got all their shots were exposed to less than 3 micrograms, according to the pediatric group.

The traditional form of the influenza vaccine contains 25 micrograms of mercury-containing thimerosal. The preservative-free pediatric influenza doses contain only trace amounts of mercury.

In September, Gov. Arnold Schwarzenegger signed legislation prohibiting the use of thimerosal in vaccines for pregnant women and children under age 3 in California. The new law takes effect in 2006.

Schwarzenegger emphasized that despite his action, ``the best available evidence states that thimerosal is safe in the levels found in vaccines,'' and that ``there are significant risks associated with the failure to vaccinate children which far outweigh any theoretical risk associated with thimerosal.''

Some parents aren't convinced, despite the best efforts by pediatricians to encourage them to get their children vaccinated against influenza.

``It isn't my intention to expose any of my patients to a potentially harmful agent,'' Bergen said. In his opinion, thimerosal is not dangerous in the small doses found in flu shots.

But, he said, ``I really wish the vaccine manufacturers could find another preservative so this issue wouldn't be there.''

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