CDC Vaccine Review Sparks Controversy Over Thimerosal Study Citation

A presentation on thimerosal, a mercury-based vaccine preservative, set to be delivered to the CDC’s advisory committee has come under scrutiny for referencing a non-existent study. The report, “Thimerosal as a Vaccine Preservative,” authored by Lyn Redwood—former leader of the anti-vaccine group Children’s Health Defense—cited a 2008 study allegedly co-authored by UC Davis Professor Emeritus Robert Berman. However, Berman confirmed that such a study was never conducted by him and said the cited findings misrepresented his actual research published in Toxicological Sciences.

The erroneous citation was first reported by Reuters, prompting the CDC to upload a revised version of Redwood’s presentation, removing the disputed slide. The controversy has intensified after Health Secretary Robert F. Kennedy Jr. recently replaced the CDC’s entire 17-member vaccine panel with eight new members, half of whom are known vaccine skeptics.

Both Republican Senator Bill Cassidy and Democratic Senator Patty Murray have urged postponement of the June 25–26 meeting, citing the panel’s lack of vetting and the absence of a CDC director. Redwood’s presentation contrasts with a separate CDC staff report reaffirming that thimerosal-containing vaccines do not cause autism or other neurodevelopmental issues.

According to CDC data, 96% of flu vaccines administered during the 2024–25 season were thimerosal-free, and only 0.3% of flu vaccines given to pregnant women contained the preservative. Kennedy, a long-time critic of vaccine safety, has previously claimed thimerosal causes brain damage—claims consistently debunked by scientific research.

The thimerosal debate highlights rising tensions around vaccine policy and misinformation, especially as newly appointed CDC advisors consider whether to recommend thimerosal-free vaccines for all pregnant women and children. Redwood has not yet responded to requests for comment.