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The persistence of the vaccine-autism controversy

A retracted journal article has reignited the debate about vaccines and autism.
A retracted journal article has reignited the debate about vaccines and autism.
Photo by ad-vantage via Flickr Creative Commons

Last week, I shared the Los Angeles Times' findings that California parents are opting out of vaccinating their kids at twice the rate they did seven years ago.

A natural follow-up question is: Why, since the supposed link between vaccines and autism has been thoroughly debunked?

I found one answer to this question on the website Retraction Watch.

Another vaccine-autism study controversy

In late August, Retraction Watch's Adam Marcus wrote that the journal Translational Neurodegeneration had pulled an article "purporting to find that black children are at substantially increased risk for autism after early exposure to the measles-mumps-rubella [MMR] vaccine."

A note on the journal's website reads:

This article has been removed from the public domain because of serious concerns about the validity of its conclusions. The journal and publisher believe that its continued availability may not be in the public interest. Definitive editorial action will be pending further investigation.

A journal spokeswoman said the organization would not comment further until the investigation is concluded. In the meantime, you can read the shelved study here, thanks to Retraction Watch.

But here are the basics: The article was a re-analysis of data that was published in a 2004 Pediatrics study, that compared ages at first MMR vaccination between children with autism and children who did not have autism. The blog Science-Based Medicine says the now-retracted re-analysis concluded that earlier MMR vaccination is associated with an increased risk of autism in African-American boys.

A CDC ‘whistleblower’

Brian Hooker, an assistant professor of biology at Simpson University in Redding and a board member of the anti-vaccination group Focus Autism, is the author of the latest paper.

Hooker appears in an AutismMediaChannel YouTube video with Andrew Wakefield, author of a now infamous 1998 study in the British medical journal The Lancet that greatly stoked the anti-vaccination movement with its claim that the MMR vaccine could cause autism. The Lancet subsequently retracted the article, and Wakefield was banned from practicing medicine in Britain for ethical lapses. 

The video features Hooker talking on the phone with a CDC researcher who worked on the 2004 Pediatrics study. In a scratchy voice, the scientist – his name is bleeped out – says he feels "great shame" because he and the other researchers left out significant findings (which were the basis of Hooker's now-retracted paper.)

"It was the lowest point in my career that I went along with that paper," the scratchy voice says, more than once.

The scientist

It's since come out that the scientist is William Thompson of the CDC. In a press release on the website of the law firm Morgan Verkamp LLC, Thompson says:

"I regret that my coauthors and I omitted statistically significant information in our 2004 article published in the journal Pediatrics. The omitted data suggested that African American males who received the MMR vaccine before age 36 months were at increased risk for autism. Decisions were made regarding which findings to report after the data were collected, and I believe that the final study protocol was not followed."

He expressly says vaccines save lives, and he would "never suggest that any parent avoid vaccinating children of any race." He clarifies:

"My concern has been the decision to omit relevant findings in a particular study for a particular sub group for a particular vaccine. There have always been recognized risks for vaccination and I believe it is the responsibility of the CDC to properly convey the risks associated with receipt of those vaccines."

The CDC says it stands behind the research and conclusions in the 2004 Pediatrics paper, which it says underwent significant review before publication.

In an e-mail statement, the CDC explains that the study presented results on two sets of children: Those who were initially recruited for the study, and a subset who could be linked with a birth certificate. Race data was available for all of the children in the birth certificate subgroup, but in the larger study group, that information was missing for 5 percent of the children without autism, and 3 percent of the children with autism, according to the CDC.

The CDC didn't explicitly connect the dots, but it would appear that the missing information was at least one reason why the authors only presented data on African-American boys and girls from the birth certificate sample, but not the entire study sample. 

The CDC says it has conducted additional studies on vaccines and autism since the 2004 paper. It says evidence from these studies, and the subsequent findings of other investigators, support the conclusion that the MMR vaccine does not cause autism, regardless of the age the shot is administered.

A social media storm 

As this story unfolded, people in the anti-vaccination movement jumped on it as further proof that the CDC is covering up information about a vaccine-autism link. Here's a sampling of the reaction on Twitter:

Back to vaccinations

So how do parents of young children make sense of all this vaccine noise?

They can start by talking to a doctor. Most will follow the guidelines set by the CDC.

Of course, there are some doctors who are sympathetic to the anti-vaccination movement, such as Orange County’s Dr. Bob Sears, the subject of an L.A. Times profile last weekend.

Reporter Paloma Esquivel writes: "About half his patients forgo vaccines altogether. To others, he offers 'Dr. Bob's' alternative and selective vaccination schedules, which delay or eliminate certain immunizations."