MMR-Autism Link Debunked

Today's New York Times editorial:



Ten years ago, a clinical research paper triggered widespread and persistent fears that a combined vaccine that prevents measles, mumps and rubella — the so-called MMR vaccine — causes autism in young children. That theory has been soundly refuted by a variety of other research over the years, and now a new study that tried to replicate the original study has provided further evidence that it was a false alarm.

The initial paper, published in The Lancet, the prestigious British medical journal, drew an inferential link between the vaccine, the gastrointestinal problems found in many autistic children and autism. In later papers, researchers theorized that the measles part of the vaccine caused inflammation in the gastrointestinal tract that allowed toxins to enter the body and damage the central nervous system, causing autism.

Now, a team of researchers from Columbia University, Massachusetts General Hospital and the Centers for Disease Control and Prevention has tried and failed to replicate the earlier findings.
These researchers studied a group of 38 children with gastrointestinal problems, of whom 25 were autistic and 13 were not. All had received the vaccine for measles, mumps and rubella. The scientists found no evidence that it had caused harm. Only 5 of the 25 autistic children had been vaccinated before they developed gastrointestinal problems — and subsequently autism. Genetic tests found remnants of the measles virus in only two children, one of whom was autistic, the other not.

The new study adds weight to a growing body of epidemiological studies and reviews that have debunked the notion that childhood vaccines cause autism. The Institute of Medicine of the National Academy of Sciences, the C.D.C. and the World Health Organization have found no evidence of a causal link between vaccines and autism.

Meanwhile, the original paper’s publisher — The Lancet — complained in 2004 that the lead author had concealed a conflict of interest. Ten of his co-authors retracted the paper’s implication that the vaccine might be linked to autism. Three of the authors are now defending themselves before a fitness-to-practice panel in London on charges related to their autism research.

Sadly, even after all of this, many parents of autistic children still blame the vaccine. The big losers in this debate are the children who are not being vaccinated because of parental fears and are at risk of contracting serious — sometimes fatal — diseases.