Great, great (loooong) article in PLoS Biology about the vaccine-autism wars, which ironically points to a hidden pitfall in applications of the precautionary principle. I love the science studies (STS) savviness:
[Medical anthropologist Sharon] Kaufman sees the enduring belief in the vaccine–autism theory as an example of what Ludwik Fleck, a clinical microbiologist with a passion for epistemology, called “an event in the history of thought”—a critical step in the way the perception of a scientific fact changes. In the US, that first step came in the form of a simple legislative action that produced new information about what was in vaccines—and quickly fed speculative theories linking them to autism.
Ok, I have got to do graduate study in STS. Otherwise I’m never going to read the copy of Fleck’s Genesis and Development of a Scientific Fact that’s been on my bookshelf for like three years.
In the US, fears centered around the ethylmercury-containing preservative thimerosal after a 1999 government report revealed that three childhood vaccines—diphtheria, tetanus, acellular pertussis (DTaP); Haemophilus influenzae type b (Hib); and hepatitis B—might expose infants to more mercury than anyone had realized.
The ill-fated precaution…:
Given the uncertainty about ethylmercury’s toxicity, Neal Halsey, director of the Institute for Vaccine Safety at Johns Hopkins University, urged vaccine policymakers at the CDC and American Academy of Pediatrics (AAP) to remove thimerosal from vaccines as a precautionary measure and to maintain public confidence in their safety. The agencies agreed, and vaccine manufacturers responded quickly; by March 2001, no children’s vaccines contained thimerosal.
Anticipating the FDA’s release of its findings, the AAP issued a statement explaining its decision as an effort to minimize children’s exposure to mercury, asserting that “current levels of thimerosal will not hurt children, but reducing those levels will make safe vaccines even safer”. Unfortunately, Kaufman says, “rather than reassuring parents, the statement fueled public fears and prompted all sorts of questions.”
… fueled the highly speculative speculation:
Several months later, Medical Hypotheses—an unconventional journal that welcomes “even probably untrue papers”—received and later published a purely speculative article called “Autism: a novel form of mercury poisoning”. Two of the authors, Sallie Bernard, a marketing consultant, and Lyn Redwood, a nurse, had just launched the parents’ advocacy group SafeMinds to promote their thimerosal hypothesis. Although their now debunked theory appeared in a journal that openly eschews peer review and evidence-based observations, several parent advocacy groups still cite it as evidence that mercury in vaccines causes autism.
And the rest is history.
If you are at all interested in the subject, read the full piece, by writer Liza Gross. Tons of information in there. Like this bit:
Sadly, studies suggest that the burden of lowered immunization rates will likely fall disproportionately on poor people living in crowded conditions, hotbeds of disease transmission, and exacerbate existing health disparities among minority populations—where kids go unvaccinated not by choice but because of limited access to health services.
Did somebody say, “‘Yes we can’ vaccinate our kids”?
Oh yeah: I wonder if Medical Hypotheses takes literary theory.