McGill University Health Center scientists examined patterns between the developmental disorder and vaccines in 28,000 children and reported their findings in the journal Pediatrics.
Their research revealed that autism rates were actually higher in children given shots after thimerosal, a mercury-based preservative, was eliminated from shots. No connection was found between autism and the MMR combination vaccine.
According to Professor Simon Baron-Cohen, an autism expert at Cambridge University, more work was needed to explain why autism rates were rising. He said, "There may also be some as yet unidentified environmental factor, but the new study suggests MMR and thimerosal are ruled out.'
While the incidence of autism was reported to be one in 2,500 children before the 1980s, now the figure has come close to one in 250. The late 1990s saw the rise of theories that linked the MMR jab to autism because some researchers believed the three-in-one vaccine overloaded the immune system. While that research has since been discredited, immunization rates have dropped in recent years, as parents feared for their children's safety.
"We hope this study will finally put to rest the pervasive belief linking vaccines with development diseases like autism," lead researcher Dr. Eric Fombonne. He also added that the rise in autism rates was probably caused by a broader definition of autism and greater awareness of the disorder.
However Jackie Fletcher of Jabs, a support network for parents who believe their children have been injured by vaccines, said the study still did not disprove the thimerosal link. Fletcher said, 'What we need, and what we have always called for, is a full and open review into the link so we can establish once and for all what the truth is.'