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Children's Vaccines Health Center

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Did CDC Conspire to Hide Vaccine Risk?

'Simpsonwood Conspiracy' Claims Debunked; Concerns Remain

The Simpsonwood Conference

Kennedy's version of what happened is that the experts conspired to hide the Verstraeten data. From the meeting transcript, he selected phrases that seemed to prove his point. Then Kennedy said that the CDC bribed the Institute of Medicine to whitewash the issue (the IOM's 2001 report found no convincing evidence linking thimerosal to autism; its 2004 report reached the same conclusion).

A close reading of the publicly available transcript leaves a far different impression than Kennedy's selective excerpts suggest. You can read it here.

In the end, the Simpsonwood consultants voted that the Verstraeten study could neither confirm nor rule out a link between thimerosal and autism, and strongly called for more study.

By the time of the ACIP meeting 13 days later, Verstraeten and colleagues had largely completed a planned second phase of their study. Essentially, the same study was repeated in a different HMO.

This time, there was no warning signal. Taken together, the two studies confirmed the consensus of the Simpsonwood meeting: Because they could not establish a definite cause and effect between thimerosal and autism, further research urgently was needed to confirm or reject the link between the two.

The ACIP then unanimously voted to continue the ongoing transition to thimerosal-free vaccines, but not to explicitly recommend against the use of vaccines containing thimerosal or to postpone vaccinations until thimerosal-free versions became available.

Simpsonwood and Vaccine Safety

Reading the Simpsonwood transcript, it’s hard to see the conspiracy Kennedy describes. Paul Offit, MD, recalls being interviewed by Kennedy and infuriated at being misquoted by him.

Offit, chief of infectious diseases and director of the vaccine education center at Children's Hospital of Philadelphia, is co-inventor of the rotavirus vaccine now sold by Merck. A staunch defender of vaccination -- and a member of the ACIP in 2000 -- he's a frequent target of anti-vaccination groups.

"To believe that the Simpsonwood meeting was a conspiracy, you have to believe the people who sat around that table -- eminent toxicologists and pediatricians included -- you have to believe they were in league to hide the truth," Offit tells WebMD. "Whereas if you read that transcript, you'll see they were trying to understand the issue and where to go from there."

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