David Reif, now a biologist at NC State, realized his old paper had taken on a dangerous second life when he saw it cited—not in the scientific literature, but in a court case.
The paper was titled “Genetic Basis for Adverse Events after Smallpox Vaccination,” and it came up in 2016 when a vaccine-skeptical doctor tried to argue that it explained her patient’s development delays. The court was not persuaded, but Reif’s co-authors began hearing of yet other doctors using DNA tests to exempt patients from vaccines. Just this month, San Francisco’s city attorney subpoenaed a doctor accused of giving illegal medical exemptions from vaccination, based on “two 30-minute visits and a 23andMe DNA test.” On anti-vaccine blogs and websites, activists have been sharing step-by-step instructions for ordering 23andMe tests, downloading the raw data, and using a third-party app to analyze a gene called MTHFR. Certain MTHFR mutations, they believe, predispose kids to bad reactions to vaccines, possibly even leading to autism—a fear unsupported by science.
This interest in MTHFR can be traced right back to Reif’s 2008 paper, which linked a variant of the gene to “adverse events” after smallpox vaccines. It was a somewhat intriguing result then. A decade later, however, James Crowe, the senior author of the paper and the director of the Vanderbilt Vaccine Center, offers a blistering assessment of his own study: “It’s just not even a valid study by today’s methodology.” To use it for granting vaccine exemptions now, he says, is “illogical and inappropriate.”