Questions & Answers
Anthrax - The Anthrax Vaccine
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Anthrax Vaccine-Ingredients

  1. What are the ingredients of the anthrax vaccine?
    Anthrax vaccine is a sterile product made from filtrates of microaerophilic cultures of an avirulent nonencapsulated strain of Bacillus anthracis. These bacteria are grown with very little oxygen (microaerophilic conditions). The bacteria cannot cause disease themselves (they are avirulent). They are from a strain of anthrax that does not have a capsule around the bacterial cells (they are nonencapsulated). This means that the vaccine is the solution that results after filtration of a culture of anthrax bacteria. If you’ve ever seen percolated coffee, you know that liquid coffee is the filtrate and the coffee grounds are what are left in the filter. In this example, the vaccine is like the cup of coffee. Anthrax vaccine is known officially to the Food & Drug Administration (FDA) as "Anthrax Vaccine Adsorbed," generating its abbreviation "AVA." Adsorbed refers to the fact that the vaccine is deposited on the surface of ("adsorbed to") a chemical called aluminum hydroxide. Aluminum hydroxide is added as an adjuvant to the vaccine to increase the amount of antibodies that the body makes in response to vaccination. Anthrax vaccine is a cell-free filtrate vaccine, which means that it contains no whole bacteria, neither live nor dead. The bacteria used to make the vaccine cannot cause disease themselves. For these two reasons, it is impossible to contract the anthrax disease from the anthrax vaccine. The final product is formulated to contain 600 micrograms aluminum per 0.5ml, added as aluminum hydroxide in 0.85% sodium chloride. The product is formulated to contain 25 mg/mL benzethonium chloride and 100 mg/mL formaldehyde, added as preservatives.

  2. Why is aluminum in anthrax and other vaccines?
    Aluminum is an adjuvant. The word adjuvant comes from the Latin, meaning "to help." Adjuvants are added to vaccines to increase antibody responses to vaccination. Aluminum salts are the only kind of adjuvant so far licensed by the FDA and the only kind of adjuvant used in anthrax vaccines for humans in the United States. Anthrax vaccine contains aluminum hydroxide, as do FDA-licensed diphtheria, Haemophilus influenzae type b, hepatitis A, hepatitis B, Lyme disease, pertussis, and tetanus vaccines.

  3. What is benzethonium chloride?
    Benzethonium chloride is used as a preservative in the anthrax vaccine. It is also a common component in other injectable and nasal medications (such as thrombin, ketamine, orphenadrine [Norflex], and butorphanol [Stadol]). Benzethonium chloride is sometimes also called Phemerol, a trade name.

  4. Does anthrax vaccine contain mercury?
    No. The preservative of anthrax vaccine is benzethonium chloride.

  5. Formaldehyde is not approved for human consumption. Why is it used in the anthrax and other vaccines?
    Material Safety Data Sheets correctly warn people not to swallow formaldehyde. Small amounts of formaldehyde are approved by the FDA for use in manufacturing several vaccines, including vaccines against anthrax, diphtheria, hepatitis A, influenza, Japanese encephalitis, and tetanus. A small amount of formaldehyde, less than 2 parts per 10,000 (0.02%), is permitted by FDA to remain in the anthrax vaccine. Formaldehyde has been used in vaccine manufacturing since the 1960s, if not earlier. Literally billions of people around the world have been given tetanus toxoid processed with formaldehyde (as anthrax vaccine is), which is recognized as safe. FDA closely monitors all the ingredients and processing steps of all vaccines and other medications before they can be distributed for widespread use. Material Safety Data Sheets (MSDS) are a method to explain chemical hazards, according to OSHA standards (see For any given chemical, health hazards vary by amount of chemical (concentration), duration of exposure (time), and route of exposure (skin, stomach, lungs, etc.). FDA's decision to permit formaldehyde to be present as residues in vaccines is based, in part, on the low concentrations and infrequent exposures involved. While it might not be prudent to have formaldehyde contact the skin every day at work, or to inhale formaldehyde fumes repeatedly, a few minute doses of formaldehyde in vaccines are recognized as safe.

  6. Does the anthrax vaccine contain pork or egg products?
    Anthrax vaccine adsorbed is a sterile, cell-free (filtered) bacterial vaccine that contains no live or dead organisms. It is not made from or with pork or egg products.

  7. Does the anthrax vaccine contain any fetal tissue?
    No human tissues of any kind are used in the process of making the anthrax vaccine.

  8. Does the anthrax vaccine contain squalene?
    In September 2000, DoD became aware of FDA test results finding trace amounts of squalene in three out of three US vaccines tested: anthrax, diphtheria, and tetanus. The level of squalene identified by the FDA test is so minute that it is likely the result of squalene in the oil of a fingerprint not cleaned from lab glassware. The trace level of squalene found by the FDA in anthrax vaccine is less than the concentration normally present in human blood (250 parts per billion).

  9. Does the anthrax vaccine use squalene as an adjuvant?
    No, the adjuvant in the anthrax vaccine is aluminum hydroxide.

  10. Is the Food & Drug Administration concerned about the quantity of squalene found in these vaccines?
    No. In Congressional testimony on 3 October 2000, FDA's Mark Elengold said that the trace quantities of squalene detected were "within the realm of both naturally occurring and safe."

  11. For More Information:

    Food & Drug Administration. Biological products; Bacterial vaccines and toxoids; Implementation of efficacy review. Federal Register 1985;50:51002-117.

    Food & Drug Administration. Biological products; Bacterial vaccines and toxoids; Implementation of efficacy review. Federal Register 2004;29:78281-93.