With further changes to the recommended U.S. vaccination schedule likely to occur in the coming year under the leadership of Secretary of Health Robert F. Kennedy Jr., his department's recent study of one vaccine additive in particular—aluminum salts—could provide insight into what's to come.
Earlier this month, members of the Centers for Disease Control and Prevention's vaccine advisory committee – who did Kennedy choose? after the previous group was fired—suggested delving into concerns about aluminum salts, even though major studies have shown them to be safe. Andrew Nixon, a spokesman for the Department of Health and Human Services, told NBC News that the committee is “reviewing the body of scientific evidence regarding aluminum and other possible contaminants in children's vaccines.”[s]”
Likewise, the statement that appeared on the CDC website reported last month that HHS was investigating whether aluminum in vaccines could be linked to autism.
Aluminum salts are not an “impurity” in vaccines: the compound is added as an adjuvant, an ingredient that enhances the body's immune response to the vaccine, allowing a lower dose to be used. Almost a century of experience has shown that it is safe for this purpose. Aluminum salts are naturally present in soil and water, and the amount children are exposed to from vaccines is negligible compared to total daily exposure through food. (Exposure through infant formula or breast milk higher than exposure to vaccines in the first six months of life.)
“It's not the kind of thing you wrap food in at a barbecue. … Their goal is simply to help the immune system respond a little more strongly to this vaccine,” said Dr. Michelle Fiscus, chief medical officer of the Association of Immunization Managers, a nonprofit that supports government vaccination programs.
“Aluminum adjuvants have made vaccines very, very effective and have helped us significantly reduce suffering, disease and death,” she added.
Skeptical or negative statements about aluminum have emerged repeatedly during federal health announcements and meetings in recent months. President Donald Trump said in September that aluminum was being “taken out of vaccines” during a news conference where he and Kennedy warned that Tylenol should be used during pregnancy. may be associated with autism. (Most scientific studies have not found such a connection.)
“Who the hell wants that stuff pumped into their body?” Trump spoke about aluminum.
Then, during a meeting of the CDC's vaccine advisory group, Dr. Tracy Beth Hoeg, acting director of the Food and Drug Administration's Center for Drug Evaluation and Research, argued for adopting the vaccination schedule Denmark uses, which is less frequent than the U.S., in part because it would reduce exposure to aluminum.
“I don’t think we have data to show there is a set safe amount. [of aluminum] which children can receive up to 2 years old and up to 18 years old,” Høeg said.
Some public health experts are concerned that the aluminum investigation is part of a broader campaign to restrict access to or approval of some childhood vaccines.
Last week, HHS delayed a planned announcement on children's health until the new year. Details are not yet known – CNN reported that the Trump administration is considering reducing the number of recommended childhood vaccines to more closely match those in Denmark, citing an unnamed source “familiar with the plans.” Several other media outlets subsequently reported the same thing, although NBC News has not confirmed the plan.
The CDC's Vaccine Advisory Committee has already voted in favor. stop recommending hepatitis B vaccine for all newborns, and, as a consequence, CDC now advises women test negative for the virus to decide whether to get vaccinated with their health care providers.
Changing vaccine recommendations based on concerns about aluminum salts would be a flimsy justification, several public health experts said. Even in Denmark, many recommended vaccines contain aluminum salts, including vaccines against human papillomavirus (HPV), pneumococcal disease, tetanus and whooping cough.
Of the CDC-listed pediatric vaccines that not included in the Danish universal guidelinesOnly three vaccines—hepatitis A, hepatitis B, and meningococcal vaccines—contain aluminum salts. The others—respiratory syncytial virus (RSV), rotavirus, influenza, and chickenpox—do not.
The vaccine that anti-vaccination activists most often and incorrectly associate with autism—the combined measles, mumps, and rubella vaccine—also does not contain aluminum salts.
A study of more than 1.2 million children in Denmarkpublished in July in the Annals of Internal Medicine, found no link between aluminum salts in vaccines and neurodevelopmental disorders, including autism.
But Kennedy, who made unsubstantiated claims that aluminum in vaccines is linked to increased rates of allergies and autism in children, called for the paper to be retracted.
“A closer look reveals that the study is so deeply flawed that it functions not as science but as a deceitful pharmaceutical industry propaganda gimmick,” he said. wrote in an editorial on TrialSite News.
Kennedy argued that the study excluded some children who may have been at risk and did not include a control group. However, the Annals of Internal Medicine supported the study and stated that there is no reason to cancel this.
Kennedy, a longtime vaccine critic, was involved in lawsuits against the pharmaceutical company Merck over allegations related to its HPV vaccine (which contains aluminum salts), but after taking office he said all royalties earned would go to one of his sons. His focus on aluminum began while he was chairman and chief litigator of anti-vaccination group “Protecting Children's Health”. The group has argued for years that thimerosal, a mercury-based preservative, is linked to autism, and Kennedy said in podcast appearance in 2020 that aluminum replaced thimerosal in some vaccines, leaving them toxic.
In fact, the ingredients serve different purposes, and aluminum salts have been used in vaccines for almost a century. Meanwhile, thimerosal was largely removed from childhood vaccines in 2001, and under Kennedy's leadership, HHS in July extracted ingredient from approximately 5% of flu vaccines it was still there.
A recent analysis Representatives of the World Health Organization have not found a link between autism and vaccines containing thimerosal or aluminum.
“There is a constant movement of the goalposts to try to implicate vaccines in these diseases, and there simply is no science to back up these claims,” Fiscus said.
In 2021 Kennedy said food blogger Mikhail Peterson that all vaccines containing aluminum have a “negative risk profile” and that the brains of children with autism are “laden with aluminum.” He also suggested that children develop food allergies because “we create allergies by pumping them full of aluminum.”
A large German office in 2011, however, found no increased risk of allergies in vaccinated children and even found a decrease in the incidence of hay fever among this group. In 2023 the study showed There was a positive association between vaccination-related aluminum exposure and persistent asthma, but the results could not be replicated and the scientists said the study did not adequately control for confounding variables.
In response to growing uncertainty about aluminum salts in vaccines, Dr. Seth Ari Sim-Son Hoffman, a physician-scientist at Stanford University School of Medicine, decided to re-analyze the existing data along with some of his colleagues. Team conclusions published this month in the journal Pediatrics found no serious safety problems with aluminum-containing vaccines. Side effects were mainly limited to redness and swelling at the injection site.
“When you see the same 'no' result or 'no' association across multiple countries, across multiple studies and over a million children, it's really very clear and encouraging,” Hoffman said.
The current schedule of childhood vaccinations in the United States, he added, is “supported by compelling evidence in terms of safety and effectiveness.”
