A controversial decision by a newly appointed federal vaccine advisory committee has signaled a shift in government health guidance, aligning with the long-standing goals of anti-vaccine activists. At a recent meeting, the Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices (ACIP), whose members were installed by Health and Human Services Secretary Robert F. Kennedy Jr., voted to effectively remove a preservative called thimerosal from recommendations for flu shots.
This move, based on a single presentation from a vaccine critic with ties to Kennedy’s advocacy group, has drawn sharp criticism from public health experts. They argue the decision disregards decades of scientific evidence confirming the safety of thimerosal and raises concerns about potential negative impacts on vaccine access and cost.
RFK Jr.’s Long Fight Against Thimerosal
The vote marks a significant achievement for RFK Jr., a prominent critic of vaccine safety and founder of the anti-vaccine advocacy group Children’s Health Defense. For years, Kennedy has campaigned against the use of thimerosal, which he claims is dangerous because it metabolizes into a form of mercury in the body. He has publicly stated his belief that this ingredient can harm children’s brains, a claim unsupported by scientific consensus.
Kennedy’s appointment of the new ACIP panel, which occurred after he dismissed the previous members, has been seen as a direct pathway to enacting his priorities within federal health policy. This controversial vote is viewed by many as a demonstration of how his influence is beginning to shape official government guidance.
A Vote Against Settled Science?
Thimerosal has been used since the 1930s as a preservative in multi-dose vaccine vials to prevent bacterial contamination. By the early 2000s, it was removed or reduced to trace amounts in most U.S. childhood vaccines, not due to safety concerns but as manufacturers increasingly shifted to thimerosal-free single-dose vials. However, it remains in some multi-dose flu vaccine formulations. The vast majority of flu shots administered today are already thimerosal-free.
Despite the scientific consensus, which includes numerous studies and analyses concluding thimerosal is safe at the levels used in vaccines and has no link to conditions like autism, the new ACIP panel voted against recommending its continued use. Critics highlighted that the decision followed a presentation from Lyn Redwood, a former leader of Kennedy’s anti-vaccine group who is not a physician and whose presentation was reportedly filled with inaccuracies and misleading statements that have been widely debunked. Experts noted that the presentation seemed to conflate ethylmercury (the form thimerosal metabolizes into, considered safe) with methylmercury (a different, toxic form found in certain fish).
Public health advocates expressed surprise and alarm that the issue, which they considered resolved decades ago based on extensive research, was abruptly added to the agenda and voted upon without the usual rigorous review process involving expert work groups that analyze data and cost-benefit analyses over months.
Potential Consequences and Expert Concerns
While the immediate impact of the vote may be limited due to the prevalence of thimerosal-free flu shots, public health experts warn of potential negative consequences. Multi-dose vials, which typically contain thimerosal, are often less expensive and easier to store and use for mass vaccination clinics and in settings like rural medical facilities or safety-net systems. Removing the recommendation for these vials could potentially lead to increased costs and decreased availability of flu shots in some areas, making access harder.
Critics, including pediatrician Cody Meissner, the sole panel member to vote against the change, argued that the risk posed by influenza is significantly greater than the “nonexistent” risk from thimerosal. They voiced concern that limiting the availability of multi-dose options could hinder vaccination efforts.
Beyond the thimerosal vote, the panel indicated plans to examine the entire childhood vaccine schedule and re-evaluate recommendations for other immunizations, moves also sought by anti-vaccine advocates. Experts view these actions as part of a concerning trend under Kennedy’s influence, potentially disrupting long-established public health policies based on settled science.
Concerns were raised about the panel’s composition and discussions, with some members expressing skepticism about the safety and efficacy of vaccines, a stark contrast to the scientific consensus upheld by bodies like the American Academy of Pediatrics, which refused to participate in the meeting. Public health leaders worry that questioning established vaccine safety could further erode public trust, potentially leading to decreased vaccination rates and the resurgence of preventable diseases that have been controlled for decades.
This controversial thimerosal decision, driven by advocacy that disregards established scientific evidence, highlights broader concerns among medical and public health communities about the direction of federal health policy and vaccine guidance under the influence of individuals with histories of challenging vaccine safety science.
