Autism>Cause of Autism Part III
In a controversial article in June 2005, Robert F. Kennedy, Jr. described research suggesting that it is not the vaccines themselves, but a
mercury-based preservative called thiomersal, used in some vaccine preparations (although not MMR), that may be a cause of autism. Kennedy argued
that autism was first observed in children who were born around the time of introduction of thiomersal into mass-produced vaccines, and that the
incidence of autism in the United States is well correlated with the amounts of thiomersal children receive during their first two years of life.
Kennedy also noted that there is a low reported incidence of autism in the Amish, who do not immunize their children. Kennedy states that is
an exception, the rare child who was immunized. However, the CDC has described a link between thiomersal and autism as 'unlikely'.
In 1999 the Public Health Service (including the CDC, FDA, and NIH) recommended that thiomersal no longer be used in vaccine preparations.
While it was by 2005 utilized in only a very few childhood vaccines, it has not been established that autism rates have dropped significantly.
The CDC and some medical organizations continue to assert that no available evidence supports a causal link between thiomersal and autism.
Critics have in turn claimed that the CDC analysis demonstrates deliberate bias in the CDC research.
For example, an analysis by Madsen et al. in Demark noted that the incidence of autism remained fairly constant while thiomersal was being
phased out and started to rise beginning in 1991, even after thimerosal was discontinued in 1992. Critics of this analysis point out that the
methodology was biased. Dissenters to the Denmark data point out a significant increase in autism rates among children whose childhood vaccines
contained thiomersal. However, in Madsen et al.'s study, the amount in the vaccinations actually decreased while autism rates increased
(specifically, during the period 1961–1970, infants had received a total of 400 µg of thiomersal by the age of 15 months, and during the period
1970–1992, infants had received a total of 250 µg at 10 months of age).
The California Department of Developmental Services (DDS), considered to have the best reporting system for autism in the US, has reported
unprecedented decreases in the caseload increase. The caseload increase went from 734 during the second quarter of 2005 to 678 during the third
quarter of 2005, a 7.5% decline in one quarter. Note that the total caseload handled by the state is still increasing, but the recent trend
points to a deceleration in the trend. For example, from the 2nd to the 3rd quarter of 2004, the caseload went from 25,020 to 25,769 (a increase
of 749 clients). Between the 1st and 2nd quarter of 2004, the caseload increased from 24,297 to 25,020 (a increase of 723 clients).
These variations have led to speculation that removal of thiomersal from vaccines in California is starting to pay off. Others point out they
are unremarkable and may simply be an indication that the awareness curve is starting to level off, and that the rate of caseload increase should
be expected to decrease to population growth levels (1.6% annual) eventually. Caseload increase between 2004 and 2005 was about 10%.
A study published in the March 2006 issue of the Journal of American Physicians and Surgeons (JPANDS) by Dr. Mark Geier claimed to show that
"new cases" of autism in California dropped as much as 35% following removal of thimerosal from vaccines. However, the study did not document
incidence drops, and its definition of "new cases" is known to be flawed.
A study published in May 2006 by Dr. Mark Geier et al. indicates that the trends of newly diagnosed neurodevelopmental disorders (NDs) such as
autism reported to VAERS "correspond directly to the expansion and subsequent contraction of the cumulative mercury dose to which children were
exposed from TCVs through the U.S. immunization schedule."
A study due to be published in July 2006 claims that the MMR vaccinations are definitely not the cause of autism and Asperger Syndrome.
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