Aluminum is used in many common vaccines, including hepatitis A, hepatitis B, DTaP, Hib, HPV, pneumococcal, meningococcal B, and tetanus-containing vaccines. It acts as an adjuvant, a substance that strengthens the immune response so the vaccine works more effectively. Not all vaccines contain aluminum, and the amounts vary by dose.
Complete List of Aluminum-Containing Vaccines
The following vaccines currently manufactured in the U.S. contain aluminum salts, listed with the amount per dose:
- Pneumococcal vaccine: 0.125 mg per dose
- Hib (Haemophilus influenzae type b) vaccine: 0.225 mg per dose
- Hepatitis A (pediatric): 0.225 to 0.25 mg per dose
- Hepatitis A (adult): 0.45 to 0.5 mg per dose
- Hepatitis B (pediatric): 0.225 to 0.5 mg per dose
- Hepatitis B (adult): 0.5 mg per dose
- Hepatitis A/Hepatitis B combination: 0.45 mg per dose
- DTaP (diphtheria, tetanus, pertussis): 0.33 to 0.625 mg per dose
- DTaP/polio/Hep B combination: up to 0.85 mg per dose
- DTaP/polio/Hib combination: 0.33 mg per dose
- Td (tetanus-diphtheria, adult): 0.53 to 1.5 mg per dose
- Tdap (tetanus, diphtheria, pertussis booster): 0.33 to 0.39 mg per dose
- HPV (human papillomavirus): 0.5 mg per dose
- Japanese encephalitis: 0.25 mg per dose
- Meningococcal B: 0.25 to 0.52 mg per dose
- Meningococcal ABCWY: 0.25 to 0.5 mg per dose
The ranges exist because different manufacturers use slightly different formulations. Combination vaccines, which bundle multiple immunizations into a single shot, also contain aluminum when any of the individual components require it.
Vaccines That Do Not Contain Aluminum
Several widely used vaccines are made without aluminum adjuvants. Live virus vaccines generally don’t need them because the live (but weakened) virus already triggers a strong immune response on its own. This category includes the MMR (measles, mumps, rubella) vaccine, the varicella (chickenpox) vaccine, the rotavirus vaccine, the live nasal spray flu vaccine, and the yellow fever vaccine.
Other aluminum-free vaccines include the inactivated polio vaccine given on its own, seasonal injectable flu shots, COVID-19 mRNA vaccines, and the shingles vaccine. If you want to know whether a specific brand contains aluminum, the package insert (available on the FDA website) lists every ingredient.
Why Aluminum Is in Vaccines
Aluminum salts have been used as vaccine adjuvants for over 70 years. They help the immune system mount a stronger, longer-lasting response to the weakened or inactivated germs in a vaccine. Without an adjuvant, some vaccines simply wouldn’t produce enough immunity to be protective, or they’d require more doses.
The traditional explanation was that aluminum creates a slow-release “depot” at the injection site, keeping the vaccine’s active ingredient available longer so immune cells have more time to respond. More recent research has complicated that picture. Studies found that removing the depot after injection didn’t significantly reduce the T and B cell immune responses, suggesting aluminum also activates the immune system through other pathways that aren’t fully mapped out yet.
How the Body Processes Vaccine Aluminum
Aluminum from a vaccine is injected into muscle tissue, where it dissolves into the surrounding fluid, enters the bloodstream, distributes through tissues, and is filtered out through the kidneys into urine. Animal studies using traceable aluminum isotopes detected it in the blood within the first hour after injection. The rate of absorption depends on the specific form of aluminum salt used. Aluminum phosphate, for instance, is absorbed roughly three times faster than aluminum hydroxide.
One point worth understanding: injected aluminum is handled very differently from aluminum you swallow in food or water. When you eat aluminum (which is naturally present in many foods, drinking water, and antacids), only about 0.3% is actually absorbed into the body. The rest passes through your digestive tract. Injected aluminum, by contrast, is fully absorbed at the injection site. Research published in the Journal of Trace Elements in Medicine and Biology found that infants up to six months of age actually take in more aluminum internally from vaccines than from food, water, and formula combined, once you account for body weight and the low intestinal absorption rate of ingested aluminum.
What Large Studies Show About Safety
The safety of aluminum adjuvants has been studied extensively in large populations. A 2025 review from the American Academy of Pediatrics summarized the current evidence across several major health concerns.
A Danish study of more than 1.2 million children born between 1997 and 2018 looked at cumulative aluminum exposure from childhood vaccines and found no link to autism spectrum disorder or other neurodevelopmental outcomes, with no dose-response relationship. The same cohort showed no increased risk of asthma or allergic disease between vaccinated and unvaccinated children. A separate German cohort of over 15,000 children found no increased risk of atopic disease among vaccinated children and actually noted a decrease in allergic rhinitis diagnoses.
One U.S. observational study did report a small association between cumulative vaccine aluminum before age 2 and persistent asthma diagnosed between ages 2 and 5, but the effect sizes were small and the finding was not replicated in the larger Danish and German studies. The AAP’s overall conclusion: the sum of high-quality evidence does not support a relationship between vaccine aluminum and allergic diseases.
For autoimmune disease, rates of autoimmune diagnoses in vaccinated populations have been comparable to background rates in the general population. A study of more than 18,000 patients receiving repeated aluminum-adjuvanted allergy shots found fewer subsequent autoimmune diagnoses than in over 400,000 matched patients who received other treatments. And a meta-analysis of seven studies covering more than 6,300 people found no evidence linking aluminum-containing antacid use to Alzheimer’s disease.