"Study finds possible link between autism and mercury preservative in vaccines," screams the headline of the L.A. Times. It seems like a bad, recurring dream: why won't these people go away?
A little historical overview is in order:
Thanks to now-discredited "research" by the UK team of Dr. Andrew Wakefield in 1998, parents of youngsters diagnosed with autism spectrum disorders (ASD) were lead to believe that thimerosal, a preservative found at that time in several childhood vaccines, might have been responsible for their childrens' developmental abnormality. Since then, multiple studies have been done, and many more analyzed, seeking to prove or disprove a link between thimerosal (which contains ethyl mercury) and ASD. The overwhelming body of research clearly eliminates any such link.
Two additional points:
1. the Wakefield study was recently disowned by The Lancet, the generally esteemed journal that published it in '98; and
2. thimerosal was removed from children's vaccines in 1999 -- except for tiny amounts remaining in flu shots, and this too will soon be gone. Since the elimination of mercury from vaccines, there has been no reduction in ASD rates -- indeed, it seems to be increasing in frequency, contrary to what one would expect if mercury had been the cause.
Concerning the present study generating the alarming headlines, which was perpetrated by a group at Columbia University and is reawakening fears and accusations among parents: this is a mouse study -- imagine how difficult it must be to diagnose autistic behavior _in a mouse_! Furthermore, the mice that exhibited aberrant behavior, ostensibly as a result of exposure to ethyl mercury, were not just garden-variety (no pun intended!) mice -- these were mice with known immune system abnormalities already inbred. Only these "special" mice reacted to the thimerosal injections with what the researchers described as behavior compatible with what would be ASD in humans. But there is no known overlap between ASD and auto-immune disease in humans, so the analogy fails yet again.
This is not to say that there might not be some sub-group of infants who are vulnerable to toxicity from some vaccine or combination of vaccines -- it would be impossible to completely eliminate that fear. But the history of unwarranted fear generated among parents, provoked by irresponsible "researchers" and even government officials, leading to parents' refusal to allow their children to get potentially lifesaving vaccinations, is out of proportion to any such minute risk.
Among the erudite medical and scientific bodies that have already denied any link between ASD and thimerosal is the Institute of Medicine, which issued a report only a few weeks ago reiterating its stance. A spokesperson for the IOM noted that the group had already seen this Columbia report and discarded it.
But that has not, apparently, stopped the reporters and headline writers from going ahead with the alarmist warnings. Just when we thought it was safe to go back into the pediatrician's office...
Gilbert Ross, M.D., is Medical and Executive Director of the American Council on Science and Health.
