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Thimerosal in Vaccines: History, Science, and Public Health Impact
How a harmless ingredient in vaccines became a favorite target of the anti-vaccine crowd.
I clearly remember falling and cutting a deep gash in my leg when I was a child. My grandfather told me to wash the wound with water and then see him inside the house. He told me to sit down on a kitchen chair while he took out a small vial from a drawer. “This is going to sting,” he said as he applied some of the red solution to the wound. It sure did sting. (And that’s probably why I remember it.)
The solution was called “Merthiolate,” and it was an antiseptic that contained thimerosal. Merthiolate was banned in the United States in the 1990s because too many children were getting poisoned from ingesting it… And because there are better ways to treat cuts and scrapes than a surgical-grade antiseptic. Nevertheless, I’ve seen it in other countries recently.
But let’s talk about thimerosal. Thimerosal has been around for almost a century, long enough to get a starring role in both global vaccine programs and some pretty heated public debates. It’s an organomercury compound, meaning that it contains mercury bound to an organic (carbon-containing) molecule. It is used mainly as a preservative, and it made vaccines safer and more…
