Study Linking Autism to Gut Inflammation and MMR Vaccine Retracted
A study done in the UK by Dr. Andrew Wakefield and colleagues (title: Ileal-lymphoid-noduler hyperplasia, non-specific colitis, and pervasive developmental disorder in children) originally published in 1998 by the British medical journal The Lancet was retracted (withdrawn from the published record) by the publisher last Wednesday, Feb 3, 2010.
This paper represents the only published study to link the MMR (measles, mumps and Rubella) vaccine and gut inflammation and autism spectral disorders (ASDs). The publication and several press conferences by Dr. Wakefield is blamed for scaring parents and kicking off the anti-vaxxer movement.
The study itself sampled only 12 children, and claimed that all of the children had been diagnosed with developmental regression on the autism spectrum soon after receiving the MMR vaccine (although there are allegations that this is not true and that the children showed signs of ASD before the vaccinations). The study found an association between gut inflammation (ileocolitis) and developmental regression and concluded that the MMR vaccine was responsible for development of ASDs in children with this inflammation.
Controversy surrounded the study since since it’s publication 12 years ago. Early critics claimed that the study was poorly done. It did not have enough participants, lacked proper controls, and the conclusions drawn over-reached the amount of data that the study provided. In response to this criticism, ten of the twelve study authors asked to have their names withdrawn from the study, publishing a “retraction of an interpretation” in The Lancet in 2004. Basically, Murch et al (the other authors of the study) agreed that their study’s methods were flawed and that there was not enough evidence to conclude that the MMR vaccine was harmful to children or that the vaccine was linked to behavioral problems associated with ASDs. Drs. Wakefield and Harvey did not sign the retraction of interpretation letter.
In addition to the critiques on the quality of the science in the study, there were allegations that the study was not done ethically. Whenever a scientific study involves people, especially children, the study design has to be thoroughly described to, and approved by, an independent “human subjects” committee at the institution where the research will take place. The committee sees that patients will not be harmed during the study, and that proper procedures are in place so that patients understand and consent to all tests. Dr. Wakefield’s ethics during the 1998 study were the subject of a two and a half year investigation by the General Medical Council (GMC). The GMC is a non-profit, independent organization that regulates good medical practice in the UK. At the end of January 2010, the GMC released its verdict, saying that Dr. Wakefield had acted unethically and without regard for the best interests of the children involved in the study. They cited him and two other study authors for not having the proper medical qualifications to do the spinal taps he performed on some of the children in the study, and for not having proper institutional board approval.
The Lancet cited the GMC’s decision to sanction Dr. Wakefield for his irresponsible and unethical behavior as a reason for retracting the 1998 paper. The journal did not make this decision lightly. Retracting an article is serious business. It’s only done in extreme circumstances and with strong evidence of misconduct or data tampering.
The GMC also cited evidence that prior to the study Dr. Wakefield had been paid by lawyers representing parents who believe their children were harmed by MMR. The GMC said that Dr. Wakefield did not disclose this conflict of interest to either the institutional review board or to the parents of the children in the study. Dr. Wakefield has not denied the connection to parents’ advocates, but does deny that there was a conflict of interest on his part.
The GMC and The Lancet did not comment on the validity of the research itself, only on the behavior of Dr. Wakefield and his colleagues. However, it is important to understand that Dr. Wakefield’s conclusions are not supported by a growing body of newer, better studies. There are a number of new studies showing that MMR and ASDs are not linked, including a paper published in 2008 directly contradicting the gut inflammation hypothesis proposed by Dr. Wakefield.
Will these new studies and the misconduct charges against Dr. Wakefield shut down the anti-vaxxer movement and convince parents that the MMR vaccine is safe? Probably not in the near future. There is still a lot of fear and misunderstanding out there. Let’s continue the discussion, get scientifically valid information out there, and help parents make the best choices for their kids and their community.