Studies: No Link Between Autism, Vaccines
Preservative in Childhood Vaccines Not a Cause of Autism, Researchers Find
The Newest Evidence continued...
For other disorders, there was no evidence of an association with thimerosal.
In fact, premature birth was the biggest factor in developmental disorders, with 5% of preterm children and 2% of full-term children having problems. Also, boys were more likely to have these disorders, he notes.
However, a greater number of short-lived tics was found among children who received all three doses of the DPT/DT vaccine within their first year. Although an association "cannot be ruled out," it is unlikely a "true finding" since tics would be accompanied by other developmental disorders, Andrews writes.
The Big Picture
To put all the evidence into perspective, Sarah K. Parker, MD, with Children's Hospital and University of Colorado Health Sciences Center in Denver, reviewed 12 studies published between 1966 and 2004. Only four studies found a link between autism and vaccines, and those were critically flawed -- so flawed that they were rendered invalid, she writes.
The bulk of evidence "does not support" an association between thimerosal-containing vaccines and autistic disorders, writes Parker.
"Determining the cause of autism is important for future diagnosis, treatment, and prevention. However, as the evidence reviewed here suggests, these efforts may be substantially more productive if they are redirected to other hypotheses."