In January 2011, the British Medical Journal (BMJ) called the 1998 study by Andrew Wakefield, which proposed a link between the measles, mumps and rubella (MMR) vaccine and autism “an elaborate fraud.” This bad study has led to long-lasting damage to public health.
The now discredited study, published in The Lancet, the medical journal that disclosed the original research, fueled the concern about MMR and autism, panicked many parents and led to a sharp drop in the number of children getting vaccinations.
The Wakefield study was a case series of 12 children. It reported a proposed “new syndrome of enterocolitis and regressive autism associated this with the MMR as an “apparent precipitating event”.
The findings and inconsistencies concerning Wakefield’s research were investigated and described in great detail by investigative reporter Brian Deer in two articles published in the BMJ. Deer was able to identify subjects and access patient data. He discovered that the hospital’s clinicians and pathology service had found nothing to implicate MMR but that Wakefield had reportedly altered, misreported and misrepresented diagnoses, histories and descriptions of the children which made it appear that a syndrome had been discovered.
The study not only had significant limitations including lack of controlled population, recall bias, selection bias, temporality (exposure must come before the manifestation of the condition), etc., but was also flawed in many ways:
- Only 1 of 9 kids said to have regressive autism clearly had it. Three had no form of autism
- Contrary to the paper’s assertion that all the kids were normal before the vaccination, 5 had some sort of preexisting developmental problems before their vaccination
- Behavioral problems that the study said showed up days after vaccination didn’t actually appear until months later in some kids, a fact that undercuts the causality of vaccination (wrong latency or time interval between exposure and response).
- The children were not randomly selected for the study. They were reportedly pre-selected through MMR campaign groups.
- In any case, a case series (one of the lowest levels in the hierarchy of scientific evidence) report of 12 children would not justify the conclusion that MMR causes autism because it simply doesn’t have numbers or enough scientific weight to do so.
Additionally, there was an issue of potential conflicts of interest before the study even began. Wakefield was hired as an expert by lawyers who were suing drug companies that manufactured the MMR vaccine over alleged vaccine injury. Some of the children involved in the study where children of parents who were suing.
Ultimately, reproducibility was a major issue with this study. The results of the study could not be replicated by other labs thus undermining the validity of the Wakefield study findings. A decade of subsequent research has basically cleared the MMR vaccine of any connection to ASD. Since the study was published, 10 of the 13 authors have retracted the findings. In 2010, The Lancet formally retracted the study, citing ethical misconduct on the part of the lead investigator, Dr. Wakefield.
At times the nature of science is misunderstood or misrepresented to the public. The lack of awareness of the shortcomings of a study can lead to a damaging public health scare. Unfortunately the scientific community took too long to adequately respond to the fraudulent study and the media effectively spread this bad story to the public. The result was derailed public confidence in vaccination programs that were beneficial, eradicating serious and highly contagious diseases.
The American astronomer and astrophysicist Carl Sagan once wrote that “Extraordinary claims should be backed by extraordinary evidence.” Undoubtedly, this did not happen with the Wakefield study.