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Even More Evidence That Mercury and Autism Are Not Linked


It can be a tough decision for new parents to decide whether to get their child vaccinated. Most pediatricians -- and the American Academy of Pediatrics -- will tell you immunizations are safe and vital to the health of all our children, but google “vaccine safety” and you’ll open a Pandora’s box of conflicting information. It can be hard for well-meaning parents without a medical degree to separate fact from fiction; celebrities like Jenny McCarthy, who has been vocal about her belief that the MMR vaccine gave her son autism, and controversial figures like Dr. Andrew Wakefield, who originally linked vaccines and autism but has since been discredited, further muddy the waters.

Now a new study debunks one of the major myths surrounding vaccines: that the preservative thimerosal, which contains a form of mercury called ethylmercury, causes autism. A new study, which will be published in the October issue of Pediatrics, followed more than 1,000 children, comparing mercury exposure with rates of autism, and found no correlation. 18 other epidemiological studies have also investigated the possible connection between autism and vaccines, and found no link.

As a precaution, manufacturers have worked over the last ten years to remove thimerosal from most vaccines (or reduce it to trace amounts), with the exception of the flu vaccine, which is available without the preservative upon request. It’s important to note, however, that while methylmercury found in some types of fish can build up in the body and harm the developing brain of a growing child, the ethylmercury in thimerosal does not build up in the body.

Vaccines are not 100% effective on their own; on average about 95 percent of the protection comes from the shot, but the remaining 5 percent comes from living in a community where there are low disease rates. So for vaccines to work, immunization rates must be high so the few people that unable to be vaccinated –- infants or children with compromised immune systems -- will be protected by what’s called “herd” immunity. When vaccine rates drop, deadly diseases can re-emerge – as we’ve seen recently with the whooping cough epidemic in California. Still, fears about the safety of vaccines persist.

Read up on all vaccines – including the MMR, flu shot and DtaP – here.