Vaccine Preservative Not Linked to Neurological Deficits
Study did not examine autism spectrum disorders
WEDNESDAY, Sept. 26 (HealthDay News) -- Early mercury exposure from thimerosal is not associated with later deficits in neuropsychological outcomes in children, although autism spectrum disorders were not examined, according to a report in the Sept. 27 issue of the New England Journal of Medicine.
William W. Thompson, Ph.D., from the U.S. Centers for Disease Control and Prevention in Atlanta, and colleagues assessed 42 neuropsychological outcomes (excluding autism spectrum disorders) in 1,047 children aged 7 to 10 years and their association with mercury exposure from thimerosal prenatally, within 28 days of birth and during the first seven months.
The researchers found few significant associations between mercury exposure and neuropsychological outcomes, most of which were small and almost equally divided between positive and negative effects. For example, performance on one measure of language was better and performance on one measure of attention and executive functioning was worse in children with higher prenatal exposure. Similar associations were observed in children with higher exposure in the seven months after birth.
"Our study does not support a causal association between early exposure to mercury from thimerosal-containing vaccines and immune globulins and deficits in neuropsychological functioning at the age of 7 to 10 years," Thompson and colleagues conclude.