Disease & Vaccine Information

What is Anthrax Vaccine?

Updated August 13, 2022


The anthrax vaccine (Biothrax manufactured by Emergent BioSolutions, Inc.) is FDA approved for use in persons between 18 and 65 years of age who are at high risk of exposure to anthrax. It can also be used in this population after a potential or confirmed exposure to anthrax but must be given in conjunction with antibiotic therapy. No anthrax vaccine is approved for persons under 18 or over 65 years of age.1

Read the Product Information Insert

NVIC strongly recommends reading the vaccine manufacturer product information insert before receiving any vaccine, including the anthrax vaccine. Package inserts are published by drug companies making vaccines and list important information about vaccine ingredients, reported health problems (adverse events) associated with the vaccine, and directions for who should and should not get the vaccine.

Links to the anthrax vaccine package insert is available below, or you can ask your doctor to give you a copy of the vaccine package insert to read before vaccination. It is best to ask your doctor for a copy of the package inserts for the vaccines you are scheduled to receive well before your vaccination appointment.

Biothrax, Anthrax Vaccine Adsorbed

 Ages: Anthrax is approved for use in adults between 18 and 65 years of age

 Vaccine ingredients: cell-free filtrates of microaerophilic cultures of an avirulent, nonencapsulated strain of Bacillus anthracis, 83kDa protective antigen protein, aluminum hydroxide, sodium chloride, benzethonium chloride, and formaldehyde.

Commonly reported adverse events: redness, swelling, and pain at the injection site, arm motion limitation, muscle aches, fatigue, and headache.

Reported serious adverse events: anaphylaxis, angioedema, rash, urticaria, pruritus, erythema multiforme, anaphylactoid reaction, Stevens-Johnson syndrome (a severe skin and mucus membrane reaction), paresthesia syncope, dizziness, tremor, ulnar nerve neuropathy, lymphadenopathy, nausea, malaise, pain, cellulitis, flu-like symptoms, insomnia, pruritis, rash, urticaria, flushing, arthralgia, arthropathy, myalgia, rhabdomyolysis, and alopecia.

Biothrax anthrax vaccine is a Pregnancy Category D vaccine, which means that there is evidence of harm in human studies or fetal risk demonstrated in pre- or post-marketing surveillance data.  Pregnant women should not be vaccinated with Biothrax unless the possible benefits of vaccination outweigh the risks. Vaccination of a breastfeeding mother is cautioned as it is not known whether the vaccine is excreted in human milk.

Biothrax has never been evaluated for safety or efficacy when given with any other licensed vaccine product.2

The CDC’s Advisory Committee on Immunization Practices (ACIP) current recommendations for anthrax vaccination.

Pre-exposure prophylaxis

Anthrax vaccine is approved to be administered intramuscularly (IM) as 3-dose primary series (0, 1, and 6 months) with an initial 2- dose booster (12 months and 18 months). A yearly booster dose is recommended for persons considered at high risk for infection (lab workers handling anthrax, military personnel). For persons who have completed the initial five doses and are not considered high risk but would like to maintain vaccine acquired protection, ACIP recommends a booster dose every three years.3

Post-exposure prophylaxis

Anthrax vaccine can be administered to persons with known or suspected anthrax exposure as a 3-dose series (0, 1, and 4 weeks) in conjunction with antibiotic therapy. ACIP recommends that anthrax vaccine be administered by subcutaneous (SC) injection because higher levels of vaccine acquired antibodies occur within four weeks; however, IM injection is still acceptable.4

AV7909 – Anthrax Vaccine Absorbed with CpG 7909 adjuvant

Emergent BioSolutions is currently in phase 3 testing of an anthrax vaccine specifically for post-exposure prophylaxis. This experimental vaccine uses the CpG 7909 adjuvant to bind to the Toll-like receptor 9 to enhance the body’s immune response to the anthrax antigen. The current clinical trials are evaluating a product containing 0.5 ml of anthrax vaccine and 0.25 ml of CpG 7909 adjuvant administered at 0 and 2 weeks, in conjunction with antibiotics.5

Cytosine phosphoguanine (CpG) is a synthetic form of DNA that mimics viral and bacterial genetic material. Only one FDA-approved vaccine, Heplisav-B Hepatitis B vaccine, uses a CpG adjuvant -  CpG 1018. The FDA twice rejected licensing of Heplisav-B due to outstanding safety concerns. In 2013, the FDA rejected the vaccine due to concerns that this adjuvant could trigger autoimmune disorders. It was rejected again in November 2016 due to concerns over cardiovascular events and deaths. One year later, in November 2017, the FDA approved the vaccine despite unresolved safety concerns. In pre-licensing clinical trials, those who received Heplisav-B had a 7-times higher risk of heart attack than those receiving the control vaccine, Engerix-B hepatitis B vaccine.6

If approved, AV7909 would be added to the Strategic National Stockpile. The CDC has submitted a request for pre–Emergency Use Authorization (EUA) to FDA for permission to use AV7909 in addition to antibiotic therapy in the event of an emergency should the supply of Biothrax be limited. This authorization would allow the use of an unapproved medical product or allow for an unapproved use of an approved medical product. Under the proposed EUA guidelines, AV7909 would be administered by intramuscular injection to persons between 18 and 65 years of age with known or suspected anthrax exposure as a 2-dose series (0 and 2 weeks) in conjunction with antibiotics.7

 


References:

[1] Emergent BioDefense Operations Lansing LLC. Package Insert and Information for Patients – Biothrax. Feb. 20, 2018.

[2] Emergent BioDefense Operations Lansing LLC. Biothrax. U.S. Food and Drug Administration Feb. 20, 2018.

[3] Bower WA, Schiffer J, Atmar RL, et al. Use of Anthrax Vaccine in the United States: Recommendations of the Advisory Committee on Immunization Practices, 2019. MMWR Dec. 13, 2019; 68(4):1–14.

[4] Bower WA, Schiffer J, Atmar RL, et al. Use of Anthrax Vaccine in the United States: Recommendations of the Advisory Committee on Immunization Practices, 2019. MMWR Dec. 13, 2019; 68(4):1–14.

[5] Bower WA, Schiffer J, Atmar RL, et al. Use of Anthrax Vaccine in the United States: Recommendations of the Advisory Committee on Immunization Practices, 2019. MMWR Dec. 13, 2019; 68(4):1–14.

[6] Parpia R. FDA Licenses New Hepatitis B Vaccine Despite Big Safety Concerns. The Vaccine Reaction Aug. 3, 2018.

[7] Bower WA, Schiffer J, Atmar RL, et al. Use of Anthrax Vaccine in the United States: Recommendations of the Advisory Committee on Immunization Practices, 2019. MMWR Dec. 13, 2019; 68(4):1–14.

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