The hypothesis that autism is linked to the measles, mumps and rubella vaccine has been around for the last 10 years. It suggests that the MMR vaccine, which is a tiny bit of a live virus, can cause inflammation in the intestines, resulting in toxins leaking into the bloodstream and damaging the developing brain.
"I saw it with my own son," Anderson said. "He was sick during the shots. He remained sick. He began having GI problems. He began losing language... and then he was diagnosed with autism. I think they are all related."
But, a study reported today in the Public Library of Science, a peer-reviewed journal, says the theory is not true. Columbia University researchers found no trace of the virus in the vast majority of the autistic children studied.
"We find no evidence to support a link between a measles vaccine, intestinal difficulties and autism," said Dr. Mady Hornig, associate professor of epidemiology and director of Translational Research, at Columbia's Mailman School of Public Health Center for Infection and Immunity.
In fact, it turned out that most of the children had the intestinal problems and signs of autism even before they received the measles vaccine.
Dr. Marie McCormick of the Harvard School of Public Health said these results are definitive and significant.
"This is the nail in the coffin," she said. "The final bit of research we were looking for to finally discredit this link between the measles vaccine and autism" is proven. But there have been dozens of studies over the years debunking a link between vaccines and autism and the controversy has still continued.
The National Autism Association released a statement today calling the study "flawed" and saying that it "fell far short of what the public needs to prove safety of the MMR vaccine."
"This is exactly the type of study we've come to expect from the CDC [Centers for Disease Control and Prevention]," said NAA Research Committee co-chair Laura Bono. "One where a sweeping conclusion is made that can't be supported by the study itself."
Many parents remain skeptical and worried about the safety of these vaccines; some refuse to have their children vaccinated, which has resulted in a higher incidence of the disease.
Of the 123 American cases of measles this yearly, nearly 90 percent were among people who had not been vaccinated. Even with this latest study, many families remain unconvinced and continue to call for more research to discover what vaccines might have done to their children.
"My son's blood work specifically points to some sort of maladaptive state because of the MMR," Anderson said. "The study doesn't convince me at all one way or the other."