Debate Rages Anew on Vaccine-Autism Link

Dr. Pauline Filipek, associate professor of clinical pediatrics and neurology at the University of California Irvine School of Medicine, and her colleagues conduct research into a possible connection.

A special court on Thursday said that the measles vaccine is not to blame for autism in children.

(ABC News Photo Illustration)

"Mercury has long been known to be a mitochondrial toxin, and could potentially interact with underlying genetic vulnerability of deficient mitochondria," she said. "That said, there remains no epidemiological data that we are aware of that implicates vaccination in autism or in mitochondrial disorders."

And vaccine experts said the victory for the Polings may represent a defeat for an important public health measure. Dr. William Schaffner, professor and chairman of preventive medicine at Vanderbilt University, said he believes the concession should not have been made until more evidence suggesting exactly how the vaccines may have contributed to Hannah's condition come to light.

"It appears that the judges in this case have not only made a legal decision but also a medical and scientific decision," he said. "I don't believe the court's role is to make these decisions."

"Legal action does not equate with proof," agreed Dr. Ira Rubin of Naperville Pediatrics in Naperville, Ill. "How many times have defendants in cases been found guilty and later found innocent when DNA testing is done?"

Does Compensation Mean a Connection?

This case, as well as other cases involving possible injury brought about by a vaccine, are handled under the National Childhood Vaccine Injury Act of 1986. The act created a no-fault system in which people with grievances, such as the Polings, would file injury claims against the federal government rather than sue the companies that made the vaccine or the health care providers who administered it.

A "special master" appointed by the U.S. Court of Federal Claims reviews these cases to determine whether vaccines were more likely the cause of the injury at hand. If the government chooses not to rebut the claim by showing that the vaccine probably was not responsible for the injury, the claim is approved and an award is made.