Saying you know and being wrong is obviously a bad thing.
Sen. John McCain, R-Ariz., declared that "there's strong evidence" that thimerosal, a mercury-based preservative that was once in many childhood vaccines, is responsible for the increased diagnoses of autism in the U.S. -- a position in stark contrast with the view of the medical establishment.
But, sometimes turning an "I don't know" statement into a "we don't know" statement is the wrong answer, although politicians love to use the phrase when they lack information. Obama and Clinton misstated science in this way:
"We've seen just a skyrocketing autism rate. Some people are suspicious that it's connected to the vaccines. This person included. The science right now is inconclusive, but we have to research it."
Senator Hillary Clinton, in response to a questionaire from the autism activist group A-CHAMP, wrote that she was "Committed to make investments to find the causes of autism, including possible environmental causes like vaccines." And when asked if she would support a study of vaccinated vs. unvaccinated children, she said: "Yes. We don't know what, if any, kind of link there is between vaccines and autism - but we should find out."
We can only hope that the candidates become better informed before they make policy decisions in this area.
Note: Two legal cases pressing an autism-vaccine link have made headlines recently.
One involved the highly unusual case of a thimersol preserved vaccine being administered to a pregnant woman in a manner pre-approved by the FDA and made headlines for abusive litigation tactics the Plaintiffs' lawyer directed at a blogger. Childhood vaccines, of course, are generally not administered in utero.
The other involved a similarly highly unusual case of a vaccinated child with a rare metabolic disease in addition to autistic symptoms, in which a vaccine compensation board chose to make an award rather than allow further expert witness and research intensive litigation in the unique case. The advocates for the child had argued that the combination of the vaccine and the metabolic disease may have had some connection to the autism symptoms. The child advocate's argument suggested that the extensive research showing a lack of an autism-vaccine link might to be applicable to a specially vulnerable child with a metabolic disease.