The federal "vaccines court" ruled Friday in three separate cases that the mercury-containing preservative thimerosal does not cause autism, a finding that supports the broad scientific consensus on the matter but that greatly disappointed parents who are convinced that their child's illness was caused by vaccines.
The court had ruled 13 months ago that a combination of the measles-mumps-rubella vaccine, commonly known as the MMR vaccine, and thimerosal does not cause the disorder, so the new ruling may finally close the bulk of litigation on the matter. The earlier ruling has been appealed to the U.S. Court of Appeals, and this one most likely will be also, but most experts think the court will uphold the decision.
Petitioners have not shown either that certain children are genetically hypersusceptible to mercury or that certain children are predisposed to have difficulty excreting mercury. The scientific validity of the studies on which petitioners rely has been questioned and the conclusions drawn from the studies have been criticized as unsupported. While differences that reflect the range of naturally-occurring individual variability are known to exist with respect to the responses of individuals to mercury exposure, these differences do not point toward the existence of a hypersusceptible population.
In essence, petitioners propose effects from mercury in TCVs [thimerosal-containing vaccines] that do not resemble mercury’s known effects on the brain, either behaviorally or at the cellular level. To prevail, they must show that the exquisitely small amounts of mercury in TCVs that reach the brain can produce devastating effects that far larger amounts experienced prenatally or postnatally from other sources do not. In order to account for this dichotomy, they posit a group of children hypersensitive to mercury’s effects, but the only evidence that these children are unusually sensitive is the fact of their ASD itself. In an effort to render irrelevant the numerous epidemiological studies of ASD and TCVs that show no connection between the two, they contend that their children have a form of ASD involving regression that differs from all other forms biologically and behaviorally. World-class experts in the field testified that the distinctions they drew between forms of ASD were artificial, and that they had never heard of the “clearly regressive” form of autism about which petitioners’ epidemiologist testified. Finally, the causal mechanism petitioners proposed would produce, not ASD, but neuronal death, and eventually patient death as well. The witnesses setting forth this improbable sequence of cause and effect were outclassed in every respect by the impressive assembly of true experts in their respective fields who testified on behalf of respondent.
The petitioners in this case have advanced the theory that thimerosal-containing vaccines can substantially contribute to the causation of autism, and that such vaccines did contribute to the causation of Jordan King’s autism. However, as to each of those issues, I conclude that the evidence is overwhelmingly contrary to the petitioners’ contentions. The expert witnesses presented by the respondent were far better qualified, far more experienced, and far more persuasive than the petitioners’ experts, concerning the key points. The numerous medical studies concerning the issue of whether thimerosal causes autism, performed by medical scientists worldwide, have come down strongly against the petitioners’ contentions.
