The true test of a scientific finding is reproducibility. In February 2001, I led a meeting at Cold Spring Harbor Laboratory, where Mr. Wakefield and his colleague John O’Leary reported that 91% of children with autism had measles virus gene fragments in their gut. Based on this information, we assembled a team of investigators from the Centers for Disease Control, Columbia University, Harvard, and Mr. O’Leary himself, to compare children who had both autism and GI disturbances with children who had GI disturbances alone.
We tested Mr. Wakefield’s two major findings. First, whether MMR preceded gastrointestinal complaints (presumably leading to a breakdown of the gut wall, allowing molecules to enter the blood stream and travel to the brain to cause autism) and, second, whether we could find measles virus in the gut of the majority of children with autism. Neither finding held up.
In our peer-reviewed study, published in PLOS One in September 2008, we found that only 20% of children fit the Wakefield model in receiving MMR vaccine before onset of GI disturbances and autism. We found measles virus sequences in the gut of only one child with autism and one child with only GI complaints. Two other research teams, one in the U.K. and another in Canada, were also unable to find measles virus sequences in the blood of children with autism.