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Autism-Vaccine Link: Evidence Doesn't Dispel Doubts

Many major medical groups say vaccines don't cause autism. Many parents say they do. So who's right?
By
WebMD Feature
Reviewed by Louise Chang, MD

Autism and vaccines: It's the link that just won't die.

The American Academy of Pediatrics, the CDC, the World Health Organization, and the Institute of Medicine all agree that there's probably no relationship between autism and vaccines.

But if the case is that solid, why do so many people remain unconvinced, from actress Jenny McCarthy, who went on Oprah to say she believes that a vaccination caused her son's autism and wrote a book about it, to Sen. John McCain, who, at a campaign event earlier this year, said he thought there was "pretty strong evidence" that some vaccines cause autism.

Their beliefs may have been validated in March when federal officials said that a Georgia girl was entitled to compensation because vaccines may have aggravated an underlying condition, causing autism-like symptoms.

And researchers at the National Institute of Mental Health (NIMH) said in March that they are still taking a careful look into parent concerns that vaccines are tied to the disorder.

"I think there's a lot of emotion around the issue of autism now. It engenders a lot of fear in parents and clinicians alike," Lee Sanders, MD, MPH, associate professor of pediatrics at the University of Miami Miller School of Medicine, tells WebMD.

Sanders knows that emotion firsthand, as the father of two young girls. "Until they turned 2 or 3, that was probably the thing I feared most," Sanders says, referring to autism.

Sanders strongly supports vaccines, saying their benefits far outweigh their risks. But he understands where the concern about vaccines and autism comes from.

That concern is difficult to suppress for a number of reasons. Parents are bombarded with information that can take a life of its own online. The concepts around scientific testing are difficult to understand, making it tough to separate good science from bad. Until scientists can prove exactly what causes autism, it's difficult to definitively disprove anything.

"In the absence of any answers from the scientific community, any scintilla of suggestion is going to get magnified by the social process of talking it out," Sanders says. "All you need is one individual's story and it will expand."

And when something bad happens to a child, people demand to know what or whom is to blame. "Parents are clamoring for a cause," says David Tayloe, MD, a pediatrician in Greensboro, N.C., and president-elect of the American Academy of Pediatrics (AAP).

"It's a terrible condition. It upsets families, and it upsets me." But all the fear and anger about vaccines is misplaced, he says. "There's just nothing there."

Vaccine-Autism Disconnect: MMR Vaccine, Thimerosal

The main reason why anyone talks about vaccines and autism is that some parents have noticed changes in children shortly after the children were vaccinated. Their kids seemed to be developing normally, then suddenly stopped interacting with people and lost language abilities -- a condition called "regressive" autism.

Next Article:

Would the fear of autism keep you from getting your child vaccinated?