Kennedy sharpens vaccine attacks, without scientific backing

As the federal government prepares for the next meeting of its Advisory Committee on Immunization Practices, Health and Human Services Secretary Robert F. Kennedy Jr. has intensified his attacks on aluminum vaccine components used in many shots to boost the body’s immune response. Kennedy, a longtime anti-vaccine activist before seeking public office, claims that aluminum adjuvants are neurotoxic and tied to autism, asthma, autoimmune disease, and food allergies.

But science and medicine advances a different view. Strong recommendations that parents introduce peanut-containing foods to infants early, for instance, have led to a drop in the incidence rate of peanut allergies. Since taking office, Kennedy has ordered reviews of vaccine ingredients, citing aluminum as a top concern. A discussion of “adjuvants and contaminants” is on the vaccine advisory panel’s draft agenda.

A Centers for Disease Control and Prevention webpage that for years has assured the public vaccines do not cause autism was updated Nov. 19 with new language stating that studies have not definitively ruled out a link between vaccines and autism. He has also targeted scientists who have published studies showing aluminum adjuvants are safe. In August, Kennedy denounced a large Danish study finding no link between aluminum in vaccines and childhood disease, calling it a “deceitful propaganda stunt” and demanding its retraction.

The Annals of Internal Medicine rejected the claim and refused to retract the study. And, regarding the upcoming advisory panel meeting, HHS spokesperson Emily HIlliard said ACIP “is independently reviewing the full body of evidence on adjuvants and other vaccine components to ensure the highest safety standards.” The stakes are high because Kennedy’s push to cast doubt on aluminum isn’t just about the ingredient itself. It’s part of a broader strategy to foster uncertainty about vaccine safety and lay the groundwork to challenge the National Vaccine Injury Compensation Program, which drug manufacturers say is essential to ensure a stable market for shots.

But researchers across infectious diseases, immunology, pediatrics, and epidemiology say the data is clear: Aluminum adjuvants are safe. “Aluminum is the third most common element on the Earth’s surface,” said Paul Offit, a pediatrician and director of the Vaccine Education Center at Children’s Hospital of Philadelphia. “So we’re all exposed to aluminum all the time. The water that we drink has aluminum in it. The food that we eat has aluminum in it.” Vaccines add only a tiny amount of aluminum to the body — a combined total of about 8 milligrams — after the schedule of childhood vaccines is complete. Offit said that over the first 18 years of life, people naturally take in about 400 milligrams of aluminum from everyday sources.

“I don’t know why there is so much concern,” said Rajesh Gupta, a former FDA vaccine scientist. “Aluminum gets distributed in the body everywhere. It is ultimately excreted by the kidneys in the urine. So, it is not that aluminum stays in the body.”

The aluminum in vaccines isn’t foil or metal. It’s a compound of aluminum salts, such as aluminum hydroxide or aluminum phosphate, that help the vaccine work better. It’s a bit like zinc in cold tablets: Patients don’t swallow chunks of metal, instead ingesting a zinc salt that dissolves safely in the body.

In vaccines, these aluminum salts give the immune system an extra nudge so it learns to recognize the target germ more effectively. When injected, the vaccine stays near the injection site and causes mild, short-lived inflammation that summons immune cells. Those cells pick up the vaccine antigen, a harmless piece of a virus or bacterium, and carry it to nearby lymph nodes. There, the adjuvants show it around like a wanted poster so the body can identify and destroy the germ quickly.

Harm HogenEsch, a professor of immunopathology at the Purdue University College of Veterinary Medicine, said that aluminum adjuvants work only when they’re injected in the same spot as the vaccine ingredient they’re meant to boost, to help nearby immune cells learn to recognize the germ. If the two shots are given in different places, he said, “you don’t see that effect.” In response to Kennedy’s claims, scientists say that anything that acts as an adjuvant can, in principle, also boost an allergic response. But that doesn’t mean aluminum-adjuvanted vaccines are turning children into food-allergic time bombs. Antigens in vaccines such as the hepatitis B surface antigen or HPV proteins are not allergens, and no food proteins are put into vaccines.

Animal studies form the basis of Kennedy’s claim that aluminum adjuvants in vaccines can create allergies. In these experiments, scientists deliberately sensitize rats or mice by injecting them with a food protein mixed with aluminum. The aluminum strengthens the immune response, but it does not cause an allergy by itself. “That’s the basis for a lot of the experimental mouse models, where you inject a food allergen with an aluminum adjuvant to sensitize the mice,” HogenEsch said. “I’m not aware of any food antigen being included in vaccines, and so I don’t really see a way by which this could happen.”

Ross Kedl, a professor of immunology and microbiology at the University of Colorado Anschutz School of Medicine, went further, noting that there is no plausible route for vaccines to create a peanut allergy out of thin air. “Someone would have had to mix peanut proteins in with the actual vaccine prior to injection.”