COLUMN -- Thimerosal issue hits the radar screen

Wednesday, August 10, 2005

There have been no recent government press conferences to reaffirm our safety from an outer space invasion. Neither has a Spielberg-like invasion been debated on "Meet the Press." Despite characterization of its supporters as conspiracy-obsessed refugees from Area 51, the theory that the mercury-based vaccine preservative thimerosal accounts for a significant rise in diagnosed cases of autism is now playing in those public forums. That is a very good thing.

Late last month, one day before the group Unlocking Autism sponsored a modest Washington, D.C., rally with the simple message "Giving mercury to children on purpose is stupid," the Centers for Disease Control rolled out an impressive array of officials from government health organizations and medical associations essentially to restate the case, "no it's not."

On Sunday, Dr. Harvey Fineberg, president of the National Institute of Medicine, appeared on "Meet the Press" with author David Kirby, whose book "Evidence of Harm" has made Kirby the de facto spokesman for the thimerosal theory. On a St. Paul visit this summer, Kirby expressed disappointment that although they roundly criticize his book, no government officials would appear with him to discuss its content. The CDC-sponsored press conference and Fineberg's appearance on "Meet the Press" mark a significant shift in government response. They are recognition that simply asserting the safety stamp of government authority is not an adequate response to the evidence that autism is increasing at a significant rate and that thimerosal might play a role.

As this debate moves from a discussion only among the saved, which characterized Kirby's Twin Cities appearances, it is important to clarify the terms of the controversy. It's a complex issue, but one doesn't have to be a brain surgeon to be concerned about the health policy implications.

Shorthand, the issue is often posited as "vaccines cause autism," which is neither accurate nor true. The medical profession regards "autism" as a "behaviorally defined condition" that does not have a biological cause. Autism is defined by its symptoms. The proponents of the hypothesis that thimerosal (not vaccines) causes "autism" are contending that mercury injected into infants and children can produce the same constellation of symptoms defined as "autism." The resemblance of "mercury poisoning" to "autism" are significant and can result in a misdiagnosis.

The thimerosal theory is not at odds with conventional research and treatment of the "behaviorally defined" autism. There are, however, medical and policy implications — mercury poisoning does have a biological cause and is treatable. Government immunization policy can reduce and even prevent it. It may have caused cases.

Health policy issues extend beyond the thimerosal controversy. From the government's initial approach to increasing the immunization schedule — assuming thimerosal safety without testing — to its inadequate response to controversy, systematic failures raise questions across a vast front of policy issues. On "Meet the Press" Fineberg's response to a question from host Tim Russert illustrates one point.

Russert cited a 2001 study by the Institute of Medicine that noted while then current scientific evidence neither supported nor disproved a link between thimerosal and neurological disorders in children, "It is medically plausible that some children's risk of a neurodevelopmental disorder could rise in part through increased mercury exposure from thimerosal-containing vaccines." In 2004 the institute issued a report conclusively stating that thimerosal is not associated with autism. What, asked Russert, changed in those three years?

Fineberg gave a concise and plausible explanation about the complexity of autism and new evidence surfacing. He noted in 2001 there was "a lot of suggestive information about the toxic properties of mercury and the problem of autism was incompletely understood." So, more than a decade after warnings raised by researchers about the amount of mercury in vaccines were ignored, the Institute of Medicine says it didn't completely understand the toxicity, but went ahead anyway with increasing the immunization schedule. Moreover, despite the 2001 incomplete understanding of toxicity, a biological problem, the 2004 institute study is almost entirely epidemiological, that is a statistical refutation. In other words, to prove the safety of thimerosal, the government has to do what "desperate" parents have done — take a retrospective look problem. There is no primary data on the safety of giving children mercury on purpose. If tens of thousands of children have not been damaged by thimerosal, it's dumb luck not a credit to government rigor.

That's why the thimerosal issue is important even for those without an autistic child. That's why government must address it. That's why increased public exposure is a very good thing.

Update: David Kirby offers his appraisal of the program.

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