A century after vaccine contamination deaths, the preservative thimerosal, containing mercury, was removed from most vaccines in 1999 despite lacking evidence of harm. This decision, driven by concerns about potential neurotoxicity, was made even though ethylmercury in thimerosal is less harmful than methylmercury. Recently, the CDC's vaccine advisory committee, reconstituted under new leadership, is revisiting thimerosal's role in vaccines, prompting concern from public health experts who fear the spread of misinformation. The meeting's agenda includes a presentation by a former anti-vaccine leader, raising apprehension about the politicization of vaccine safety.

Prepared by Olivia Bennett and reviewed by editorial team.