VERY LITTLE is known about autism, what causes it and exactly what it means biologically or neurologically. The disorder, characterized by impaired social, emotional and communications skills, is still diagnosed by clinical observations rather than physiological tests. The observable symptoms of autism usually appear around age 2 or 3 -- the same age when children often receive vaccines. This week a special court began hearing the first of nine test cases claiming that such timing is not a coincidence, and the litigation could spell trouble for children nationwide.
The nine cases may have implications for 4,800 similar pending cases, most of which were filed by family members who attribute their children's autism to a mercury-containing vaccine preservative called thimerosal, to the measles-mumps-rubella vaccine (MMR, which does not contain thimerosal) or to a combination of thimerosal and MMR. To date, no major studies have shown any connection between vaccines and autism, and the Institute of Medicine has rejected any causal relationship.
Still, some activists have claimed that autism rates have skyrocketed since many of these vaccines were mandated for young children. They say that the Centers for Disease Control and Prevention's recent (and alarming) finding that one in 150 8-year-old children nationwide has an autistic spectrum disorder -- up from one in several thousand diagnosed in previous decades -- represents an autism "epidemic."
But over the past decade, the accepted definition and symptoms of autism have expanded to include much milder cases and cases that would previously have been given different diagnoses, and researchers have sought out children for diagnosis whose autism probably would not otherwise have been detected. What's more, since 2001, no vaccines (except some flu vaccines) routinely recommended for children under age 6 have contained thimerosal, and autism rates do not appear to be dropping.
This from the Washington Post.