Jenny
posted by saurabh in Biology, Health! |While we’re setting fire to myths, I might as well weigh in on this whole autism/vaccination thing, which I’ve been intending to write about for months. Recently Jenny McCarthy (no pictures, sorry) appeared on the Oprah Winfrey (no pictures, sorry) show, along with Holly Robinson Peete (Earthquake, 2004) to discuss autism. Both are mothers of autistic children. Jenny told the following horror story about how she believes her son Evan became autistic:
“Right before his MMR shot, I said to the doctor, “I have a very bad feeling about this shot. This is the autism shot, isn’t it?’ And he said, ‘No, that is ridiculous. It is a mother’s desperate attempt to blame something,’ and he swore at me, and then the nurse gave [Evan] the shot,” she says. “And I remember going, ‘Oh, God, I hope he’s right.’ And soon thereafter-boom-the soul’s gone from his eyes.”
Chilling, indeed. But - do we believe it? The autism rate has certainly been galloping skyward recently, and thimerosal, the vaccine additive accused of causing autism, seems like a downright villain. It’s toxic and teratogenic, and there’s no reason to believe it’s anything but bad for humans. But it does make an effective bactericide, and so it’s included in many childhood vaccines. This seems a questionable practice, and it is, in fact being questioned - and reversed. New vaccines don’t contain thimerosal, and only the existing stock of vaccines still does. Once this dries up, no more thimerosal.
Will that mean an end to autism? Maybe, but if so, it’ll be coincidental. Thimerosal has been in widespread use in vaccines for a long time; it’s neurotoxic, certainly, but there’s no biological justification for why it would produce autism, which some evidence indicates forms early in development. And I think there’s been some pretty large nails driven into the coffin for this theory. For example, take this JAMA study:
Mercuric compounds are nephrotoxic and neurotoxic at high doses. Thimerosal, a preservative used widely in vaccine formulations, contains ethylmercury. Thus it has been suggested that childhood vaccination with thimerosal-containing vaccine could be causally related to neurodevelopmental disorders such as autism. […] Population-based cohort study of all children born in Denmark from January 1, 1990, until December 31, 1996 (N = 467,450) comparing children vaccinated with a thimerosal-containing vaccine with children vaccinated with a thimerosal-free formulation of the same vaccine.
[…] During 2,986,654 person-years, we identified 440 autism cases and 787 cases of other autistic-spectrum disorders. The risk of autism and other autistic-spectrum disorders did not differ significantly between children vaccinated with thimerosal-containing vaccine and children vaccinated with thimerosal-free vaccine (Rate Ratio (RR), 0.85 [95% confidence interval {CI}, 0.60-1.20] for autism; RR, 1.12 [95% CI, 0.88-1.43] for other autistic-spectrum disorders). Furthermore, we found no evidence of a dose-response association (increase in RR per 25 µg of ethylmercury, 0.98 [95% CI, 0.90-1.06] for autism and 1.03 [95% CI, 0.98-1.09] for other autistic-spectrum disorders). The results do not support a causal relationship between childhood vaccination with thimerosal-containing vaccines and development of autistic-spectrum disorders.
You’re not going to get more definitive than that. So: vaccines as a bogeyman are appealing, but, to quote Kanye West, “What’s the basis?”
Keep this in mind if the subject ever comes up at your local coffee table.
Loading ...
Powered by FireStats
Also, remember to hold your tongue around parents of autistic kids. That doctor was right — parents of autistic kids are desperate to understand what could cause their kids to retreat into themselves. They want an explanation — ANY explanation, even if it’s grasping at straws. I’ve had conversations with the parents of the autistic girl we know, and they are convinced that mercury-chelation therapy could work, or only giving their kids a particular brand of bottled water will help. It’s sad to see them trying to reach their kid through any means possible. The only thing that actually seems to work with that little girl is intensive therapy. But you can’t put hard scientific evidence up against parental love and expect science to win out.
“But it does make an effective bactericide”
Not entirely. It did fail in the Chiron debacle a few years back. There are other studies that show it’s not quite an effective bactericide.
“New vaccines don’t contain thimerosal, and only the existing stock of vaccines still does. Once this dries up, no more thimerosal.”
Nope, not true. The flu vaccine manufacturers are still producing almost all vaccines with thimerosal in them.
AnneS - thanks for the corrections. I’m absolutely in agreement that vaccines shouldn’t include toxic teratogens, of course. Just, this fight should be divorced from the issue of autism.
Hey, It seems we teh same obession Saurabh : we like to tackle issues separately.
You will have a hard time getting people to try and divroce one issue from an other. You will get accused of taking the wrong side while you are just saying that an issue is irrelevant to the current debate, etc…
don’t you ?