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Bad Medicine


Claim:   Data suppressed by the CDC proved that the MMR vaccine produces a 340% increased risk of autism in African-American boys.

FALSE

Example:   [Collected via e-mail, August 2014]

Is the following true: Fraud at the CDC uncovered, 340% increased risk of autism hidden from public.
 

Origins:   On 24 August 2014 a CNN iReport claiming intentional suppression of data relating to 340% increased risk of autism among specific populations of African-American boys following MMR vaccinations went viral. The story seemed to disappear mysteriously, further fueling the notion that an intentional coverup was underway.

The idea that vaccines lead to autism is not a new conspiracy theory, nor is it a particularly uncommon one. A now heavily discredited study published in the medical
journal Lancet in 1998 planted a seed of fear about vaccine safety; and despite efforts to counteract the widespread concern among worried parents, public health officials continue to encounter growing public resistance to vaccination. And the CNN iReport in question was based on a video which featured William Thompson, a senior researcher at the CDC, seemly "confessing" to anti-vaccinationist Brian Hooker about a coverup at the CDC and included material such as a claim by Dr. Andrew Wakefield (who in 1998 published a fraudulent research paper claiming a link between MMR vaccine and the appearance of autism and has since been barred from practicing medicine in the UK) asserting that the results of a study proving a link between autism and MMR (measles, mumps, and rubella) vaccinations had been "hidden" by the CDC:

The claim being put forward in the video is that earlier MMR vaccination is associated with an increased risk of autism in African-American boys and that the CDC has spent the last 13 years covering this linkage up. These charges are based the result of a "reanalysis" by Brian Hooker in Translational Neurodegeneration entitled "Measles-mumps-rubella vaccination timing and autism among young african american boys: a reanalysis of CDC data." The study which has been "reanalyzed" is from a study by DeStefano et al in 2004 published in Pediatrics entitled "Age at first measles-mumps-rubella vaccination in children with autism and school-matched control subjects: a population-based study in metropolitan Atlanta." That study was a case-control study in which age at first MMR vaccination was compared between autistic "cases" and neurotypical controls. Vaccination data were abstracted from immunization forms required for school entry, and records of children who were born in Georgia were linked to Georgia birth certificates for information on maternal and birth factors.
 

The second iReport published on 22 August 2014 explicitly claimed that the CDC had been involved in an intentional coverup:

William W. Thompson, PhD, Senior Scientist with the CDC has stepped forward and admitted the 2004 paper entitled "Age at first measles-mumps-rubella vaccination in children with autism and school-matched control subjects: a population-based study in metropolitan Atlanta," which has been used repeatedly by the CDC to deny the MMR-autism connection, was a fraud.

http://www.ncbi.nlm.nih.gov/pubmed/14754936

Dr. Thompson has admitted the 340% increase in boys receiving the MMR vaccine "on time," as opposed to delayed, was buried by himself, Dr. DeStefano, Dr. Bhasin, Dr. Yeargin-Allsopp, and Dr. Boyle ... Dr. Thompson first called and spoke with Dr. Brian Hooker, who then revealed the information to Dr. Andrew Wakefield and the Autism Media Channel.
 

On 27 August, Thompson released a statement via law firm Morgan Verkamp, LLC, confirming that he had spoken with Dr. Brian Hooker and that he had "omitted statistically significant information" from his study. Titled "STATEMENT OF WILLIAM W. THOMPSON, Ph.D., REGARDING THE 2004 ARTICLE EXAMINING THE POSSIBILITY OF A RELATIONSHIP BETWEEN MMR VACCINE AND AUTISM," Thompson's statement began:

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.

I want to be absolutely clear that I believe vaccines have saved and continue to save countless lives. I would never suggest that any parent avoid vaccinating children of any race. Vaccines prevent serious diseases, and the risks associated with their administration are vastly outweighed by their individual and societal benefits.
 

What got lost in the brouhaha over Dr. Thompson's "confession," allegations about a "cover-up" at the CDC, and threats of whistleblower lawsuits was what should have been the main point: Did collected data actually prove that the MMR vaccine produces a 340% increased risk of autism in African-American boys? The answer is no, it did not.

On 27 August 2014, Dr. Hooker's article published in the journal Translational Neurodegeneration that concluded "African American males receiving the MMR vaccine prior to 24 months of age or 36 months of age are more likely to receive an autism diagnosis" was removed from public domain due to issues of conflict of interest and the questionable validity of its methods:

The Editor and Publisher regretfully retract the article as there were undeclared competing interests on the part of the author which compromised the peer review process. Furthermore, post-publication peer review raised concerns about the validity of the methods and statistical analysis, therefore the Editors no longer have confidence in the soundness of the findings.
 

The CDC issued a statement regarding the data in question, with instructions for accessing the study at the center of the controversy. As the CDC noted, the authors of that study suggested that the most likely explanation for the moderate correlation between autism and vaccination in young children was the existence of immunization requirements for autistic children enrolled in special education preschool programs:

Access to the information on the birth certificates allowed researchers to assess more complete information on race as well as other important characteristics, including possible risk factors for autism such as the child’s birth weight, mother’s age, and education. This information was not available for the children without birth certificates; hence CDC study did not present data by race on black, white, or other race children from the whole study sample. It presented the results on black and white/other race children from the group with birth certificates.

The study looked at different age groups: children vaccinated by 18 months, 24 months, and 36 months. The findings revealed that vaccination between 24 and 36 months was slightly more common among children with autism, and that association was strongest among children 3-5 years of age. The authors reported this finding was most likely a result of immunization requirements for preschool special education program attendance in children with autism.
 

For a thorough analysis of the flaws and misinformation associated with the current CDC autism "cover-up" conspiracy theory, we recommend the posts on the subject at ScienceBlogs, which note of the claim at the heart of this matter (i.e, allegedly suppressed proof of a 340% increased risk of autism in African-American boys after MMR vaccination) that:

Vaccination data were abstracted from immunization forms required for school entry, and records of children who were born in Georgia were linked to Georgia birth certificates for information on maternal and birth factors. Basically, no significant associations were found between the age cutoffs examined and the risk of autism. I note that, even in the "reanalysis" by Brian Hooker, there still isn't any such correlation for children who are not African American boys

So is Hooker’s result valid? Was there really a 3.36-fold increased risk for autism in African-American males who received MMR vaccination before the age of 36 months in this dataset? Hooker [performed] multiple subset analyses, which, of course, are prone to false positives. As we say, if you slice and dice the evidence more and more finely, eventually you will find apparent correlations that might or might not be real. In this case, I doubt Hooker's correlation is real.

There's no biologically plausible reason why there would be an effect observed in African-Americans but no other race and, more specifically than that, in African-American males. In the discussion, Hooker does a bunch of handwaving about lower vitamin D levels and the like in African American boys, but there really isn't a biologically plausible mechanism to account for his observation, suggesting that it's probably spurious. There are multiple other studies, many much larger than this one, that failed to find a correlation between MMR and autism.

What [Hooker] has done, apparently, is found grist for a perfect conspiracy theory to demonize the CDC, play the race card in a truly despicable fashion, and cast fear, uncertainty, and doubt about the CDC vaccination program, knowing that most of the white antivaccine activists who support [him] hate the CDC so much that they won't notice that even Hooker's reanalysis doesn’t support their belief that vaccines caused the autism in their children.
 

Last updated:   3 February 2015

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