RFK Jr. Mandates Removal of Thimerosal from All U.S. Vaccines

In a significant policy shift, Robert F. Kennedy Jr., the U.S. Secretary of Health, has announced a formal requirement for vaccine manufacturers to eliminate thimerosal, a mercury-based preservative, from all vaccines distributed in the United States. This decision, which comes amidst ongoing debates about vaccine safety and public health, has drawn both support and criticism from various stakeholders across the health and scientific communities.

The announcement was made on July 23, 2025, following a recommendation from a restructured federal vaccine advisory panel, which was recently filled with Kennedy’s allies. This panel voted 5-1, with one abstention, in favor of removing thimerosal from vaccines. The move is seen as a culmination of decades of anti-vaccine campaigns that have targeted thimerosal, despite the lack of scientific evidence linking it to health risks, particularly in children.

Kennedy stated, “After more than two decades of delay, this action fulfills a long-overdue promise to protect our most vulnerable populations from unnecessary mercury exposure.” He emphasized that the removal of thimerosal aligns with a precautionary approach to public health, despite thimerosal’s long history of use in vaccines, particularly in multi-dose vials where it has been instrumental in preventing contamination.

Historically, thimerosal has been employed in vaccines since before World War II. It was controversially phased out of most childhood vaccines in 1999 as a precautionary measure, although it remained in a small percentage of adult influenza vaccines. Critics of the phase-out have argued that its removal was not justified by scientific findings, and that it inadvertently fueled anti-vaccine sentiments. According to Dr. Sarah Johnson, Professor of Health Policy at Stanford University, “The removal of thimerosal without substantial evidence of harm may send mixed messages about vaccine safety, potentially undermining public trust.”

The recent decision has raised concerns among public health experts, particularly regarding its implications for vaccine compliance and effectiveness. Dr. Emily Carter, Director of the Vaccine Research Institute, noted, “This move could complicate the vaccination landscape, especially if it leads to increased vaccine hesitancy. It is crucial that policymakers base decisions on comprehensive scientific evidence.”

The decision also presents challenges for global vaccine manufacturers, as Kennedy has urged international health authorities to follow the U.S. example. “With the U.S. now removing mercury from all vaccines, we urge global health authorities to follow this prudent example for the protection of children worldwide,” he stated. This pressure could lead to a ripple effect in vaccine formulation practices globally, potentially impacting vaccine availability and distribution, especially in low-resource settings where thimerosal is still used as a preservative in multi-dose vials.

Critics have also pointed out the potential consequences of Kennedy's appointment of allies from the anti-vaccine movement to key health advisory roles. For instance, Lyn Redwood, a former leader of the World Mercury Project and a current member of Kennedy’s advisory panel, presented arguments against thimerosal that have faced scrutiny for lacking robust scientific backing. During a recent advisory committee meeting, it was reported that a presentation from CDC career scientists, which affirmed the safety of thimerosal, was removed by Kennedy’s office.

As the U.S. embarks on this unprecedented policy change, the implications for public health remain to be fully understood. The debate over thimerosal and vaccine safety is likely to intensify, reflecting broader societal divisions over vaccination and public health policy. Future studies will be essential in assessing the long-term impacts of this decision on vaccine confidence and overall public health outcomes.