Anthrax Vaccine
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Anthrax Vaccine

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What Is Anthrax?

Anthrax is an infectious disease caused by the bacterium Bacillus anthracis. It can occur in humans when they have been exposed to contaminated animals or tissue from contaminated animals.

Anthrax is most frequently found in South and Central America, Southern and Eastern Europe, Asia, Africa, the Caribbean, and the Middle East. It has even been found in wild livestock in the United States, although it is rare. It is predominantly found in agricultural areas of these regions.

The bacteria can be transmitted to humans through inhalation, the skin, or ingestion. The bacteria can infect a human who breathes in spores from a contaminated animal, touches a contaminated animal (alive or dead), or eats undercooked meat from a contaminated animal.

Symptoms of anthrax include:

  • Skin infection that initially looks like an insect bite may occur. It then turns into an ulcer with black, necrotic skin in the center.
  • If the bacteria are inhaled, initial symptoms may seem like a common cold .
  • Anthrax that has been ingested causes severe abdominal cramping, vomiting, vomiting blood, nausea, diarrhea, and fever.

Anthrax is treated with antibiotics. If diagnosed and treated early, the disease may be cured. Without treatment or delays in starting medicine, anthrax can be fatal.

What Is the Anthrax Vaccine?

The anthrax vaccine doesn’t contain dead, weakened, or living bacteria. It is, instead, called a cell-free filtrate vaccine. This means that the bacteria used to make the vaccine cannot cause disease.

The vaccine also contains elements that allow for easy storage: aluminum, aluminum hydroxide in a solution of sodium chloride, benzethonium chloride, and formaldehyde.

It should be stored in a cool environment, 36ºF-46ºF, but it should not be frozen.

The vaccine is administered as three subcutaneous shots, given every two weeks. A follow-up shot is given at six, 12, and 18 months after the original injection. Booster injections of the vaccine are administered each year following the initial series.

Who Should Get Vaccinated and When?

The following individuals (aged 18 to 65 years) should get vaccinated. Those who:

  • Are laboratory workers that may come into contact with B. anthracis
  • Come into contact with animal meat, hide, or fur that may have been exposed to anthrax spores
  • Work with animals and animal products in areas where anthrax infection commonly occurs (not common in the US)
  • Are in the military run the risk of exposure to anthrax as a biological warfare weapon

What Are the Risks Associated With the Anthrax Vaccine?

  • Common, mild side effects include soreness or redness at the injection site
  • A more severe reaction may be significant swelling in the arm where the shot was administered
  • Rare, but serious risks include systemic reaction—This a condition usually associated with anaphylaxis, which can cause extreme allergic response, including interrupted breathing, hives, dizziness, and arrhythmic heart rate
  • Other serious adverse events may also occur.

Who Should Not Get Vaccinated?

Those who should not get vaccinated include:

  • The general public who are not at significant risk of exposure to anthrax
  • Very young children, the elderly, or people with compromised immune systems
  • Pregnant women should not be routinely vaccinated.

What Other Ways Can Anthrax Be Prevented Besides Vaccination?

  • Take precautions when dealing with animals or animal products that could possibly be contaminated with B. anthracis.
  • Begin a course of antibiotic treatment if you've been exposed to anthrax.

What Happens in the Event of an Outbreak?

It is not believed that anthrax can be transmitted from person to person. But, if an outbreak occurred and a large number of people were exposed to the bacteria, the US would administer antibiotics to everyone exposed.


South Dakota Department of Health

Vaccine and Immunizations
Centers for Disease Control and Prevention


US Centers for Disease Control and Prevention website. Available at: Accessed February 4, 2007.

US Food and Drug Administration website. Available at: Accessed February 4, 2007.

Last reviewed February 2008 by David Horn, MD, FACP

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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