Podcast: Harmful Mercury In Flu Shots? Nope. Here's The Chemistry You Should Know

By Cameron English and ChuckDinerstein — Aug 21, 2025
Health and Human Services Secretary Robert F. Kennedy, Jr. is once again warning about the supposed dangers posed by mercury-containing vaccines. "I’m proud to finally deliver on a long-overdue promise: protecting our most vulnerable from unnecessary mercury exposure," he tweeted in early August. Kennedy was celebrating the removal of the preservative thimerosal from a small fraction of seasonal flu vaccines. The problem? He bungled basic chemistry in his rush to (once again) badmouth immunization. Let's take a look.
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Join Cameron English, Dr. Chuck Dinerstein and Dr. Josh Bloom on Episode 128 of the Science Dispatch podcast as they discuss:

Mercury, the element, is no longer used in thermometers, but it remains at the center of a decades-long debate over vaccine safety, despite the science being crystal clear. At the heart of this confusion is thimerosal, a mercury-containing preservative wrongly accused of causing autism. What follows isn’t a rehash of that conspiracy theory, but rather a crash course in chemistry. It's something RFK Jr. and his CDC picks need to know.

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