The Health and Human Services Department on Wednesday said it adopted a recommendation from Secretary Robert F. Kennedy Jr.'s vaccine advisers to remove from all influenza shots a preservative that anti-vaccine activists have suggested is linked to autism.The move hinged on the widely discredited belief that the mercury-containing compound, thimerosal, is harmful at the level at which it's included in vaccines.Despite the lack of evidence of harm, most Americans who get flu vaccines already receive products without thimerosal.The latest: Kennedy, in a statement, said the action fulfilled a promise to protect vulnerable populations from unnecessary mercury exposure."Injecting any amount of mercury into children when safe, mercury-free alternatives exist defies common sense and public health responsibility," Kennedy said. "Today, we put safety first."The Centers for Disease Control customarily acts on such recommendations. But because the CDC lacks a full-time political leader, Kennedy signed the recommendation.HHS said that vaccine manufacturers confirmed that they have the capacity to replace multi-dose vials containing the preservative so that the federal Vaccines for Children program and adult vaccine supplies won't be interrupted.Kennedy's handpicked vaccine advisors voted 5-1 last month to no longer recommend that that Americans get flu shots containing thimerosal, following a presentation from a retired nurse and former president of Children's Health Defense, the anti-vaccine group with close ties to Kennedy.The panel voted to recommend that children, pregnant women and adults only get single-dose seasonal flu vaccines that are thimerosal-free.Kennedy has long promoted the belief that vaccines or other environmental factors have led to increased autism diagnoses in children.The US Department of Health and Human Services has adopted a recommendation to remove thimerosal from all influenza vaccines distributed in the United States, even though there is no clear evidence of harm from the mercury-based preservative.On July 23, the department announced that HHS Secretary Robert F. Kennedy Jr. has formally signed the recommendation, which was made last month by the US Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices (ACIP). Kennedy’s signature means that the recommendation is now federal health policy.“After more than two decades of delay, this action fulfills a long-overdue promise to protect our most vulnerable populations from unnecessary mercury exposure,” Kennedy said in the HHS announcement Wednesday. “Injecting any amount of mercury into children when safe, mercury-free alternatives exist defies common sense and public health responsibility. Today, we put safety first.”Other recommendations from ACIP’s June meeting are currently under review, according to HHS.Thimerosal was largely removed from most vaccines about 25 years ago. The US Food and Drug Administration asked manufacturers to remove it out of an abundance of caution, not because of evidence of harm, according to the CDC. All vaccines routinely recommended for young children are now available in doses that don’t have the preservative, which contains a form of mercury.Flu vaccines drawn from multidose vials still contain thimerosal in order to prevent bacterial contamination. Only about 4% of flu vaccines given in the United States last year contained thimerosal as a preservative.When ACIP voted in June to endorse thimerosal-free flu vaccines, it was among the panel’s first actions taken as a new committee that was appointed by Kennedy after he dismissed the previous panel, claiming that they had conflicts of interest.In a series of three votes, the new ACIP panel voted 5-1, with one member abstaining, to recommend that only single-dose flu vaccines be given to children, adults and pregnant women in the United States. Single-dose shots are free of thimerosal.Vaccines with thimerosal are still approved by the FDA, but ACIP recommendations are tremendously influential in how vaccines are used in the US, with implications for insurance coverage and state policies.Robert F Kennedy Jr, the US health secretary, will formally require vaccine makers to remove thimerosal from vaccines.The ingredient has been the target of anti-vaccine campaigns and misinformation for decades. Arguments against the preservative culminated in June, when a key federal vaccine advisory panel, remade with Kennedy’s ideological allies, recommended against the preservative.The recommendation goes into force upon Kennedy’s signature.There is no evidence thimerosal has caused harm, despite decades of use. The ethylmercury-based preservative was used in only about 5% adult influenza vaccines in the US, helping prevent contamination in multi-dose vials.“After more than two decades of delay, this action fulfills a long-overdue promise to protect our most vulnerable populations from unnecessary mercury exposure,” Kennedy said in a statement announcing the decision.a man in a sweat-soaked shirt and jeans stands with his son atop a mountain, RFK Jr strides into new controversy: hiking in sweltering Arizona … in jeans“Injecting any amount of mercury into children when safe, mercury-free alternatives exist defies common sense and public health responsibility. Today, we put safety first,” said Kennedy.Thimerosal is an ethylmercury-based preservative – different from the kind of mercury found in seafood, called methylmercury. Ethylmercury has a shorter half-life in the body. The amount of ethylmercury contained in a flu vaccine (25 micrograms) is about half of that contained in a 3oz serving of canned tuna fish (40 micrograms).The preservative has been used in vaccines since before the second world war. It was controversially phased out of most childhood vaccines in 1999, physicians associations said as a precautionary measure, and was contained in only a very small number of adult vaccines.Phasing out the preservative in the early 2000s was criticized by experts who argued scientific evidence did not support its removal, that it sent mixed messages and that it provided a talking point for anti-vaccine campaigners. Indeed, the preservative was targeted for years to come.That criticism came to a head in June, after Kennedy fired all 17 members of the Centers for Disease Control and Prevention’s (CDC) advisory committee on immunization practices, a federal panel that was a critical link in the vaccine distribution pipeline.Kennedy replaced the experts with eight hand-picked allies, including one directly from the anti-vaccine movement. Eventually, one appointee dropped out after a conflict of interest review.The vaccine advisory panel voted in favor of removing thimerosal on a 5-1 vote (with one abstention) after a controversial presentation from Lyn Redwood, a former leader of World Mercury Project, the predecessor to Kennedy’s group Children’s Health Defense, itself a prolific anti-vaccine campaign group.