The Claim in Context 

The claim that aluminum salts in vaccines cause autism, other neurodevelopmental conditions or serious health issues in children is a longstanding rumor intended to make vaccine ingredients sound scary. Aluminum salts are found naturally in soil, water and foods. Small amounts of aluminum salts are used in some vaccines to boost the body’s immune response, meaning lesser quantities of the vaccine and fewer doses are needed. Studies have found no significant health risks associated with the tiny amounts of aluminum salts in vaccines and have been used safely for decades.  

 

Key Facts 

  • People are exposed to aluminum through food, air, water, infant formula, medicine, cosmetics, deodorants and other consumer products. Experts estimate that people ingest about 7-9 mg of aluminum every day (equivalent in size to about 7-9 grains of sand).
  • Aluminum salts are used as an immune-boosting ingredient in the DTaP (diphtheria, tetanus, pertussis), Hib (Haemophilus influenzae type b), hepatitis A, hepatitis B, HPV, pneumococcal and meningococcal vaccines. Most of these vaccines contain less than 0.5 mg of aluminum per dose, a small fraction of most people’s daily exposure to aluminum. 
  • Aluminum in vaccines can cause minor side effects like redness and swelling in the area where the vaccine was injected.
  • The human body processes aluminum salts the same way regardless of whether they are injected in the body as part of a vaccine or ingested as part of food or water. Most aluminum is processed in the kidneys and eliminated in urine. While some aluminum remains in the body, the amounts are very low. There is ample evidence that the low levels of aluminum in vaccines are safe.
  • Aluminum toxicity is rare and unrelated to vaccines. People with aluminum toxicity usually have kidney failure (and therefore cannot properly process aluminum) and have been exposed to high amounts of aluminum over months or years. The amount of aluminum salts contained in vaccines is too small to cause a toxic effect. 
  • A study published in 2025 that evaluated health records of 1.2 million children born in Denmark between 1997 and 2018 did not find an association between aluminum in vaccines and certain health conditions including asthma, allergies (including food allergies), autoimmune disorders and neurodevelopmental conditions like autism and ADHD. 

Evidence Snapshot 

Evidence shows that vaccines with aluminum are safe and beneficial for children’s health and wellbeing. Research has not found evidence that aluminum in vaccines cause autoimmune conditions, neurodevelopmental disorders, or serious adverse events. Numerous studies have also sought to better understand how aluminum from vaccines impacts levels of aluminum in the body. One team of researchers looked at levels of aluminum in blood and hair samples from infants and did not find any correlation with immunization history. Another study indicates the amount of aluminum from vaccines and food in infants during the first year of life is significantly lower than established safe thresholds.  

Why It Matters

Like any medicine, each ingredient in a vaccine has a specific function. Certain types of vaccines, including multiple vaccines recommended for children, require an immune-boosting ingredient like aluminum. Without this ingredient, the vaccines would not work as intended. Promoting misleading claims about vaccine ingredients undermines public trust, creates unnecessary fear and ignores the many benefits of vaccines. Routine childhood immunization helps ensure children's immune systems are prepared to resist serious but preventable diseases so they can stay focused on playing and learning. When vaccination is widespread, contagious diseases have a hard time spreading. This community immunity keeps preventable diseases at bay and sets young people up for lifelong health and wellbeing. 


Experts Say:

“Routine childhood immunization helps ensure children's immune systems are prepared to resist serious but preventable diseases so they can play and learn.  Aluminum salts are naturally occurring elements that exist all around us—in food, water, and even air. When it comes to vaccines, small amounts of aluminum salts may be included to help boost the body’s immune response and ensure maximal levels of protection against harmful diseases. Vaccines are carefully researched, studied, and tested to ensure they are safe and work as intended.”


— Sean O’Leary, MD, FAAP, Member, AAP Committee on Infectious Diseases

Resources for Further Information 

ToxFAQsTM for Aluminum

Agency for Toxic Substances and Disease Registry

Vaccine Ingredients: Aluminum

Children’s Hospital of Philadelphia

Common Ingredients in FDA-Approved Vaccines

Food and Drug Administration (FDA)

Last Updated

12/04/2025

Source

American Academy of Pediatrics