Vaccine Ingredients: Aluminum

Vaccine Ingredients: Aluminum
Aluminum Q&A infographic

Aluminum is the third most abundant element after oxygen and silicon, and it is the most abundant metal, making up almost 9 percent of the earth's crust. Aluminum is found in plants, soil, water and air. Most plants have low quantities of aluminum, but a few are known to be aluminum accumulators, including some types of tea plants, grasses and orchids.

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Aluminum is used extensively in various ways:

  • Aluminum can be found in food-related products including pots and pans; storage containers, such as beverage cans; and foil.
  • Aluminum is found in numerous foods and beverages including fruits and vegetables, beer and wine, seasonings, flour, cereals, nuts, dairy products, baby formulas, and honey. Typically, adults ingest 7 to 9 milligrams of aluminum per day.
  • Aluminum is used for manufacturing of airplanes, siding, roofing materials, paints, pigments, fuels and cigarette filters.
  • Aluminum is found in health products including antacids, buffered aspirin, antiperspirants and some vaccines.

Aluminum in vaccines

Aluminum is used in vaccines as an adjuvant. An adjuvant is a vaccine component that boosts the immune response to the vaccine. Adjuvants allow for lesser quantities of the vaccine and fewer doses. The adjuvant effects of aluminum were discovered in 1926. Aluminum adjuvants are used in vaccines such as hepatitis A, hepatitis B, diphtheria-tetanus-containing vaccines, Haemophilus influenzae type b, and pneumococcal vaccines, but they are not used in the live, viral vaccines, such as measles, mumps, rubella, varicella and rotavirus.

Vaccines containing adjuvants are tested extensively in clinical trials before being licensed. Aluminum salts, monophosphoryl A (a detoxified bacterial component), QS21 (isolated from the bark of Quillaja Saponaria trees), CpG (nucleic acids), and squalene (a compound of the body’s normal cholesterol synthesis pathway) are used as adjuvants in the United States. The quantities of aluminum present in vaccines are low and are regulated by the Center for Biologics Evaluation and Research (CBER).

The aluminum contained in vaccines is similar to that found in a liter (about 1 quart or 32 fluid ounces) of infant formula. While infants receive about 4.4 milligrams* of aluminum in the first six months of life from vaccines, they receive more than that in their diet. Breast-fed infants ingest about 7 milligrams, formula-fed infants ingest about 38 milligrams, and infants who are fed soy formula ingest almost 117 milligrams of aluminum during the first six months of life.

*Note: One milligram is one-thousandth of a gram. One gram is the weight of one-fifth of a teaspoon of water.

Watch "Is There a Difference Between Aluminum That Is Injected vs. Ingested?" for more information. 

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Aluminum in Vaccine Q&A

Quantities of aluminum in vaccines

Pneumococcal vaccine

  • 0.125 milligram per dose (mg/dose)

Diphtheria-tetanus-acellular pertussis (DTaP) vaccine

  • < 0.33 to < 0.625 mg/dose

Haemophilus influenzae type b (Hib) vaccine

  • 0.225 mg/dose

Hepatitis A vaccine (Hep A)

  • 0.225 to 0.25 mg/dose (pediatrics)
  • 0.45 to 0.5 mg/dose (adults)

Hepatitis B vaccine (Hep B)

  • 0.225 to 0.5 mg/dose (pediatrics)
  • 0.5 mg/dose (adults)

Hep A/Hep B vaccine

  • 0.45 mg/dose

DTaP/inactivated polio/Hep B vaccine

  • < 0.85 mg/dose

DTaP/inactivated polio/Hib vaccine

  • 0.33 mg/dose

Human Papillomavirus (HPV) vaccine

  • 0.5 mg/dose

Japanese Encephalitis (JE) vaccine

  • 0.25 mg/dose

Meningococcal B vaccine

  • 0.25 – 0.52 mg/dose

Td vaccine

  • < 0.53 – 1.5 mg/dose

Tdap vaccine

  • 0.33 – 0.39 mg/dose

Why Is Aluminum in Vaccines? Isn’t It Dangerous?

  • Why is aluminum in vaccines? Isn’t it dangerous?

    Speaker 1: Why is aluminum in vaccines? Isn’t it dangerous?

    Paul Offit, MD: So, the reason aluminum is in vaccines, and has been really since the 1930s and 1940s, is it serves as something called an adjuvant. So, by adding aluminum what that does is that makes the vaccine more likely to produce an immune response. It also makes it so that you can give fewer doses of the vaccine and also lesser quantities of the vaccine.

    So, then the question becomes, is it harmful? And you should realize that assuming you live on the planet earth, you're going to be exposed to aluminum salts in water, aluminum salts in the food that we eat at far greater quantities than you ever would get being exposed to a vaccine. Now, a parent could say, yeah, but isn't it true that if you eat aluminum or drink aluminum salts, that a lesser quantity of that is absorbed from the intestine into the bloodstream than if you inject it directly into the arm, in which case the body doesn't have any chance to reject that aluminum? That's true. I mean, by definition, 100% of the aluminum that you give as a vaccine is going to be absorbed, whereas only about 1% of what's given, taken by mouth, either in the water we drink or the breast milk that we drink or the infant formula that we drink or the food that we eat, is going to actually then go from the intestine into the bloodstream. That is true. It's only about 1%.

    But there's so much more in your, in what you drink and what you eat than you're ever going to get from a vaccine that you can't tell that anybody's gotten a vaccine that has aluminum in it. In other words, studies that have been done looking at people who get aluminum-containing vaccines that then look at the blood levels for aluminum to see whether there's clearly been a bump in the aluminum then that is in your bloodstream, doesn't show a bump because you are eating or drinking so much aluminum on this planet. So, it isn't harmful.

    The only place in which aluminum really is harmful is in people who have kidneys that don't work well or don't work at all, and that’s where it can be a problem. And only in that situation, it's when you're taking sort of things like antacids that contain large quantities of aluminum that that can be a problem.

    So, hopefully that helps. Thank you.
Transcript Transcript

Is There a Difference Between Aluminum That Is Injected vs. Ingested?

  • Is there a difference between aluminum that is injected vs. ingested?

    Paul Offit, MD: Hi, my name’s Paul Offit. I’m talking to you today from the Vaccine Education Center here at The Children’s Hospital of Philadelphia. There’s a question that comes up about one of the adjuvants that’s used in vaccines, which is called aluminum. There are aluminum salts that are used as adjuvants.

    What adjuvants do is they lessen the number of shots that you need to get, or lessen the amount of the active ingredient in a vaccine that you need to get, or both. And, you know, people wonder whether aluminum, which is an abundant light metal, can do harm. Well certainly we’re exposed to large quantities of aluminum in the food that we eat or in the water, or anything made from water, that we drink. But people could reasonably ask, “Isn’t there a difference then between when you inject somebody with aluminum versus when you ingest aluminum, or eat it?” And the answer is yes.

    It’s actually, you’re much more likely to have aluminum in your circulation if you inject it than if you ingest it. But the point is that there’s so much more aluminum in the environment, either in the food you eat or the water you drink, than you would ever get as a shot in vaccines. That even though there is that difference between injection and ingestion, there’s logarithmically so much more aluminum that you ingest that you actually have far more aluminum in your circulation because of what you eat and drink than you would ever get from vaccines.

    Then again, usually when people have problems with aluminum, it’s because they have kidneys that don’t work well or don’t work at all. And, or are getting large quantities of antacids, which contain a lot of aluminum. Or they’re getting intravenous fluids that contain aluminum.

    So it’s really not an issue and hasn’t been. I mean, a number of groups have looked at the data on aluminum as to whether or not it’s harmful. And we’ve been using aluminum in vaccines now for 70 years. And the answer is no, aluminum salts contained in vaccines are safe.

    Thanks.
Transcript Transcript

Aluminum in other substances

Quantities of aluminum in other substances

Breast milk

  • 0.04 milligrams per liter (mg/L)

Ponds, lakes, streams

  • 0.1 mg/L

Infant formula

  • 0.225 mg/L

Soy-based formula

  • 0.46 to 0.93 mg/L

Buffered aspirin

  • 10 to 20 mg/tablet

Antacid

  • 104-208 mg/tablet

Given the quantities of aluminum we are exposed to on a daily basis, the quantity of aluminum in vaccines is miniscule. Aluminum-containing vaccines have been used for decades and have been given to more than 1 billion people without problem. In spring 2000, the National Vaccine Program Office (NVPO) reviewed aluminum exposure through vaccines and determined that no changes to vaccine recommendations were needed based on aluminum content. The Global Advisory Committee on Vaccine Safety, part of the World Health Organization (WHO), has also reviewed studies and found no evidence of health risks that would require changes to vaccine policy.

Injection vs. ingestion of aluminum

Some people wonder about the difference between exposure to aluminum from vaccines compared to that introduced through foods. As they point out, most of the aluminum contained in foods passes through the intestine without getting into the bloodstream (less than 1% is absorbed), whereas all of the aluminum in a dose of vaccine ends up in the bloodstream. While this is true, three points are important to consider:

  1. Once aluminum ends up in the blood, its source does not matter, meaning that our body processes it the same way regardless of how it arrived in the blood. As such, aluminum from food or vaccines (or any other source) will be treated similarly in the body.
  2. Aluminum is a positively charged ion, so when introduced as a salt (like in vaccines), it will quickly reassociate with a chemical that is more negatively charged than the one it came with. In our blood, transferrin is most often that “new partner” (about 90% of the time). Citrate is a second choice (about 10% of the time). Once the aluminum associates with one of these new partners, it is carried to the kidneys, where about half of it is removed from the body within 24 hours. Half of the remainder is removed by the next day, etc. This is called its “half-life,” the period it takes for half of the quantity to be removed. A small amount of aluminum does go to other parts of the body, but most of that ends up in the bones and to a lesser extent the lungs. Very small quantities end up in other tissues, including the brain (about 1%), skin, lymph nodes and elsewhere. This processing and distribution explain why the first effects of too much aluminum are seen in the bones, blood and brain.
  3. Although the relative quantity of aluminum introduced on a vaccination day may be significantly greater than that introduced by food on that day, over time, we are exposed to more aluminum from food than from vaccines because the exposure from food occurs daily. If you consider that half of the aluminum in the blood is removed from the body every 24 hours, you will realize that each day additional aluminum is introduced through food. As such, over time, most of the aluminum in the blood could be traced back to that source. In contrast, aluminum from vaccines, while greater, is only introduced a limited number of times during infancy (or even throughout one’s life).

Health effects of aluminum

The health effects of aluminum have been studied; however, few have been shown to result from aluminum exposure. Kidney dialysis patients have developed disorders of the brain and bones due to the aluminum content in intravenous fluids and antacids following years of dialysis. Both disorders have decreased in occurrence due to improvements to dialysis systems. The bone disease was due to poor absorption of phosphate in the presence of high quantities of aluminum. Children taking large amounts of aluminum-based medications have also been found to suffer from this bone disorder.

It has been suggested that some diseases involving the brain, such as Alzheimer's disease, are caused by aluminum accumulation in brain tissues. However, studies have not consistently found increased levels of aluminum leading some to hypothesize that the aluminum accumulation may be the result of tissue damage rather than the cause of disease.

In late 2022, a paper was published suggesting a possible association between aluminum in vaccines and later development of asthma; however, for several reasons these data should be viewed with caution. 

References

Goullé JP, Grangeot-Keros L. Aluminum and vaccines: Current state of knowledge. Med Mal Infect 2020 Feb;50:16-21.
Although aluminum at high doses can cause a variety of clinical manifestations, the quantity of aluminum in vaccines is too small to cause a direct toxic effect. Indeed, the quantity of aluminum in biological specimens from those receiving aluminum-containing vaccines is indistinguishable from unvaccinated subjects. The concern that aluminum in vaccines might be associated with a rare autoimmune disease called macrophagic myofasciitis has been refuted by previous studies.

Karwowski MP, Stamoulis C, Wenren LM, et al. Blood and hair aluminum levels, vaccine history, and early infant development: a cross-sectional study. Acad Pediatr 2018;18:161-165.
Children aged 9 to 13 months, excluding those who received aluminum-containing pharmaceuticals, were evaluated for blood and hair aluminum levels, vaccination history, and cognitive, language and motor development scores. The authors found no correlation between infant blood or hair aluminum concentrations and vaccine history or between blood aluminum and overall developmental status.

Ameratunga R, Gills D, Gold M, et al. Evidence refuting the existence of autoimmune/autoinflammatory syndrome induced by adjuvants (ASIA). J Allergy Clin Immunol Pract 2017;5:1551-1555.
The authors identified two studies refuting the claim for autoimmune/autoinflammatory syndrome induced by adjuvants (ASIA) as suggested by Shoenfeld and coworkers. In one study, lupus patients were found to have no increase in exacerbations after receiving a hepatitis B vaccine containing an aluminum adjuvant. A second study evaluated the incidence of autoimmune disease in more than 18,000 patients who received subcutaneous allergen-specific immunotherapy containing large quantities of injected aluminum. Patients receiving injected aluminum were found to have a lower incidence of autoimmune disease compared with controls. The authors concluded that current studies do not support the existence of ASIA.

Mitkus RJ, King DB, Hess MA, et al. Updated aluminum pharmacokinetics following infant exposures through diet and vaccination. Vaccine 2011; 29:9538-9543.
The authors found that the burden of aluminum from diet and from vaccines given according to the CDC schedule within the first year of life was well within levels considered to be safe, even when the infant was small for age (i.e., equal to or less than the 5thpercentile for weight).

Jefferson T, Rudin M, Di Pietrantonj C. Adverse events after immunization with aluminium-containing DTP vaccines: systematic review of the evidence. Lancet Infect Dis 2004;4:84-90. The authors reviewed the incidence of adverse events after exposure to aluminum-containing diphtheria, tetanus and pertussis (DTP), alone or in combination, compared with identical vaccines, either without aluminum or containing aluminum in different concentrations. In children up to 18 months of age, aluminum-containing vaccines were associated with more erythema and induration than vaccines without aluminum. They were not, however, associated with serious adverse events.

Keith LS, Jones DE, Chou CHSJ. Aluminum toxicokinetics regarding infant diet and vaccinations. Vaccine 2002;20:S13-S17.
The authors determined whether exposure to aluminum in the diet and in vaccines during the first year of life exceeded the minimal risk level (MRL) set by the Agency for Toxic Substances and Disease Registry (ATSDR). They found that the amount of aluminum received from vaccines was greater than that from dietary sources; however, this level was routinely below the MRL with the exception of brief periods immediately following vaccination. Levels of exposure slightly above the MRL were also likely to be safe given the manner in which the MRL is calculated.

Reviewed by Paul A. Offit, MD, on December 15, 2022