Health Secretary Robert F. Kennedy Jr. has already ordered a review of aluminum salts in childhood vaccines, raising questions about the U.S. vaccine schedule.
After firing the previous advisory group, Kennedy selected a new CDC vaccine advisory committee that has begun to examine concerns about aluminum salts.
Andrew Nixon, a spokesperson for the Department of Health and Human Services, told NBC News that the committee is “reviewing the body of science related to aluminum and other possible contaminants in childhood vaccines.”
A statement on the CDC website last month said HHS is investigating whether aluminum in vaccines could be linked to autism.
Aluminum salts are not a contaminant; they are adjuvants that boost the immune response to a vaccine, allowing for a smaller dose to be used.
Nearly a century of evidence has found aluminum salts safe for this purpose, and they are naturally present in soil and water.
The amount of aluminum children receive from vaccines is minuscule compared with the cumulative daily exposures from food, and exposure from infant formula or breastmilk is higher than exposure from vaccines in the first six months of life.
Dr. Michelle Fiscus, chief medical officer at the Association of Immunization Managers, said, “This is not the thing that you wrap your food in at the barbecue. … The purpose of them is to just help the immune system respond a little more robustly to that vaccine.”
She added, “Aluminum adjuvants have made vaccines very, very effective and have helped us significantly reduce suffering and sickness and death.”
Negative statements about aluminum have appeared repeatedly during federal health announcements and meetings in recent months.
In September, President Donald Trump said aluminum was being “taken out of the vaccines” during a news conference where he and Kennedy warned that Tylenol use in pregnancy may be linked to autism.
Trump said, “Who the hell wants that pumped into a body?”
During the CDC vaccine advisory panel meeting, Dr. Tracy Beth Høeg, acting director of the FDA’s Center for Drug Evaluation and Research, argued for adopting Denmark’s sparser schedule, which would reduce aluminum exposure.
Høeg said, “I do not feel like we have the data to show that there is an established safe amount [of aluminum] that children can receive before the age of 2, before the age of 18.”
Some public health experts worry that the investigation into aluminum is part of a broader push to restrict access to or approval of some childhood shots.
Last week, HHS postponed a planned announcement about children’s health to the new year, and details are not yet known.
CNN reported that the Trump administration was considering decreasing the number of recommended childhood vaccines to align more closely with Denmark’s, citing an unnamed source familiar with the plans.
NBC News has not confirmed that plan.
The CDC’s vaccine advisory committee has already voted to stop recommending the hepatitis B vaccine for all newborns, and the CDC now advises women who test negative for the virus to decide about the shot with their medical 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 those for human papillomavirus, pneumococcal disease, tetanus and whooping cough.
Of the pediatric vaccines on the CDC schedule that are missing from Denmark’s universal recommendations, just three-hepatitis A, hepatitis B and meningococcal vaccines-contain aluminum salts.
The others-respiratory syncytial virus, rotavirus, flu and chickenpox-do not.
The Varivax vaccine, which protects against chickenpox, does not contain aluminum salts.
The combination measles, mumps and rubella vaccine, the shot most frequently associated with autism by anti-vaccine activists, also does not contain aluminum salts.
A study of more than 1.2 million children in Denmark, published in July in the journal Annals of Internal Medicine, found no link between aluminum salts from vaccines and neurodevelopmental disorders, including autism.
Kennedy demanded the paper be retracted, writing in an editorial on TrialSite News, “A closer look reveals a study so deeply flawed it functions not as science but as a deceitful propaganda stunt by the pharmaceutical industry.”
Kennedy argued that the paper excluded some children who may have been at risk and did not include a control group.
Annals of Internal Medicine stood by the study and said there was no reason to retract it.
Sen. Bill Cassidy, R-La., who is a liver disease doctor, explained why he supported the CDC guidance that infants should receive the hepatitis B vaccine, as he raised concerns that the ACIP will vote to change the recommendation.
Kennedy, a longtime critic of vaccines, had been involved in lawsuits against the pharmaceutical company Merck over allegations related to its HPV vaccine, which contains aluminum salts, but since taking office he has said any fees earned would go to one of his sons.
His focus on aluminum dates back to his time as chairman and chief litigation counsel at the anti-vaccine group Children’s Health Defense, which has claimed for years that thimerosal is linked to autism.
Kennedy said in a 2020 podcast that aluminum had replaced thimerosal in some vaccines, causing them to remain toxic.
Thimerosal was largely phased out of childhood vaccines in 2001, and under Kennedy’s leadership, HHS in July pulled the ingredient from the roughly 5% of flu vaccines that still had it.
A recent analysis from the World Health Organization found no link between autism and vaccines containing thimerosal or aluminum.
Fiscus said, “There’s this constant movement of the goal post to try to implicate vaccines in the development of these diseases, and there’s just not science to back those claims.”
In 2021 Kennedy told food blogger Mikhaila Peterson that all aluminum-containing vaccines had “negative risk profiles” and that the brains of children with autism were “loaded with aluminum.”
He suggested that kids develop food allergies because “we’ve been inducing allergies by pumping them full of aluminum.”
A large German study in 2011 did not find an increased risk of allergies in vaccinated children and even identified a decrease in hay fever among the group.
In 2023, a study found a positive association between vaccine-related aluminum exposure and persistent asthma, but the results couldn’t be replicated and scientists said the research didn’t properly control for confounding variables.
In response to mounting hesitancy about aluminum salts, Dr. Seth Ari Sim-Son Hoffman, a physician-scientist at Stanford Medicine, reanalyzed existing data with colleagues.
Published this month in Pediatrics, the study found no major safety concerns with aluminum-containing vaccines, and side effects were mostly limited to redness and swelling at the injection site.
Hoffman said, “When you see the same ‘no’ finding or ‘no’ association across multiple countries, multiple study designs and over a million children, that’s really, really clear and reassuring.”
He added that the current childhood vaccine schedule in the U.S. “is backed by powerful evidence in terms of safety and effectiveness.”
Key Takeaways
- The U.S. vaccine schedule may change under Secretary Kennedy, with a focus on reviewing aluminum salts.
- Scientific studies, including a large Danish cohort and a recent Stanford analysis, find no link between aluminum in vaccines and autism or other neurodevelopmental disorders.
- Despite political and advisory pressures, the safety record of aluminum adjuvants remains robust, and experts warn that altering schedules on this basis would be unsupported.
The debate over aluminum in vaccines illustrates how policy, politics, and science intersect, but current evidence does not support a causal link between aluminum exposure from vaccines and autism.
