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Vaccines Again Linked to Form of Autism
March 8, 2007
New findings presented yesterday at a National Autism Association
meeting bolster claims that vaccines may play a role in the
development of autism spectrum disorders.
David Ayoub, MD presented data suggesting a correlation between
mercury- containing vaccines and rates of pervasive developmental
disorder (PDD), a form of autism, in Montreal.
The peak rate of one in 87 children diagnosed with PDD occurred
following the period of greatest exposure to the mercury- based
vaccine preservative thimerosal. A flattening of the rates studied is
now emerging as mercury-containing vaccines have been gradually
eliminated from the routine schedule.
This new data points out flaws in a 2006 study published in the
journal Pediatrics by Eric Fombonne, MD, et al, which found PDD rates
continued to increase even when rates of MMR vaccination and use of
mercury-containing vaccines decreased. The study population consisted
of a single Montreal school board that was an Autism Center of
Excellence, suggesting an over- ascertainment of regional diagnoses.
Dr. Ayoub and co-authors Monica Ruscitti, BA, and F. Edward Yazbak, MD
broadened the data to include all five Montreal school boards.
The earlier study also reported PDD rates in children from Montreal,
but MMR coverage data was taken from Quebec City located 265km from
Montreal. The researchers confirmed MMR coverage rates actually
increased in Montreal along with PDD, noting a sharper rise in rates
after the number of required MMR shots doubled.
The Pediatrics paper claimed there was no exposure to mercury from
vaccines post-1996 although several mercury-containing vaccines were
administered well beyond 1996. "It's irresponsible that such flawed
data was published in a medical journal. This new information confirms
a relationship between vaccines and autism that can't be explained by
better diagnosing or changing diagnostic criteria," said Karen
McDonough, NAA -- Chicago president.
Drs. Ayoub and Yazbak detailed the Fombonne study flaws in letters to
Pediatrics which the journal declined to publish. Editor Jerold F.
Lucey, MD stated in a reply, "I believe the evidence of no link
between MMR and Autism is sufficient. It's not worth publishing more
on this subject."
"This dismissal of legitimate concerns regarding data affecting those
suffering with autism is a disgrace," commented Ms. McDonough.
Source: Health Sentinel
