Anthrax is an infectious disease that’s caused by a bacteria called Bacillus anthracis. It’s rarely found in the United States, but outbreaks of illness sometimes occur. It also has the potential to be used as a biological weapon.

Anthrax bacteria can form dormant structures called spores that are highly resilient. When these spores enter the body, the bacteria can reactivate and cause serious and even fatal disease.

Continue reading to learn more about the anthrax vaccine, who should get it, and what the potential side effects are.

There’s only one anthrax vaccine available in the United States. Its brand name is BioThrax. You may also see it referred to as anthrax vaccine adsorbed (AVA).

AVA is produced using a strain of anthrax that is avirulent, which means it’s unlikely to cause disease. The vaccine doesn’t actually contain any bacterial cells.

Instead, AVA is made up of a bacterial culture that’s been filtered. The resulting sterile solution contains proteins made by the bacteria during growth.

One of these proteins is called protective antigen (PA). PA is one of the three components of anthrax toxin, which the bacterium releases during infection. It’s this release of toxins that can cause serious illness.

AVA stimulates your immune system to produce antibodies to the PA protein. These antibodies can then help to neutralize anthrax toxins should you contract the disease.

The anthrax vaccine normally isn’t available to the general public. The Centers for Disease Control and Prevention (CDC) currently recommends that the vaccine be given only to very specific groups.

These groups are people who are likely to come into contact with the anthrax bacteria. They include people ages 18 through 65 who are:

  • laboratory workers that work with the anthrax bacteria
  • people who work with animals or animal products that are infected, such as veterinary staff
  • certain U.S. military personnel (as determined by the Department of Defense)
  • unvaccinated people who’ve been exposed to the anthrax bacteria

The vaccine is given in two different forms based on pre-exposure and post-exposure to anthrax.


For prevention, the anthrax vaccine is given in five intramuscular doses. The doses are given 1, 6, 12, and 18 months after the first dose, respectively.

In addition to the initial three doses, boosters are recommended every 12 months after the final dose. Because immunity can decline over time, boosters can provide ongoing protection to people who may be exposed to anthrax.


When the vaccine is used to treat unvaccinated people who have been exposed to anthrax, the schedule is compressed to three subcutaneous doses.

The first dose is given as soon as possible, while the second and third dose are given after two and four weeks. Antibiotics will be given for 60 days alongside the vaccinations.

Used forDose 1Dose 2Dose 3Dose 4Dose 5BoosterAntibiotic
Prevention1 shot to the upper armone month after first dosesix months after first doseone year after first dose18 months after first doseevery 12 months after final dose
1 shot to the upper arm
two weeks after first dosethree weeks after first dosefor 60 days after first dose

The following people should not receive the anthrax vaccine:

  • people who have had a past serious or life-threatening reaction to the anthrax vaccine or any of its components
  • people with a weakened immune system due to autoimmune conditions, HIV, or medications such as cancer treatments
  • women who are pregnant or believe they may be pregnant
  • people who have previously had anthrax disease
  • people who are moderately to severely ill (they should wait until they recover to get vaccinated)

Like any vaccine or medication, the anthrax vaccine also has some potential side effects.

Mild side effects

According to the CDC, mild side effects can include:

  • redness, swelling, or a lump at the site of injection
  • feelings of soreness or itchiness at the injection site
  • muscle aches and pains in the arm where the injection was given, which may limit movement
  • feeling tired or fatigued
  • headache

These side effects often resolve on their own without treatment.

Rare and emergency side effects

According to the World Health Organization (WHO), the main serious side effects that have been reported include severe allergic reactions such as anaphylaxis. These reactions typically occur within minutes or hours of receiving the vaccine.

It’s important to know the signs of anaphylaxis so that you can seek emergency care. Signs and symptoms can include:

  • difficulty breathing
  • swelling in the throat, lips, or face
  • nausea
  • vomiting
  • abdominal pain
  • diarrhea
  • fast heartbeat
  • feeling dizzy
  • fainting

These types of reactions are very rare, with less than one episode being reported per 100,000 doses given.

Drug interactions

The anthrax vaccine should not be given along with immunosuppressive therapies, including chemotherapy, corticosteroids, and radiation therapy. These therapies can potentially reduce the effectiveness of AVA.

Along with the proteins that act as the active ingredient of the anthrax vaccine, preservatives and other components make up the vaccine. These include:

  • aluminum hydroxide, a common ingredient in antacids
  • sodium chloride (salt)
  • benzethonium chloride
  • formaldehyde

You may have heard about the anthrax vaccine in the news over the years. This is due to concerns in the military community regarding effects from anthrax vaccination. So what’s the story?

The Department of Defense began a mandatory anthrax vaccination program in 1998. The aim of this program was to protect troops against potential exposure to anthrax bacteria used as a biological weapon.

Concerns developed in the military community regarding potential long-term health effects of the anthrax vaccine, particularly on Gulf War veterans. So far, researchers have found no association between the anthrax vaccine and long-term illness.

In 2006, the vaccine program was updated to make the anthrax vaccine voluntary for most groups in the military. However, it’s still mandatory for some personnel. These groups include those involved in special missions or stationed in high-risk areas.

The anthrax vaccine protects against anthrax, a potentially deadly disease caused by a bacterial infection. There’s only one anthrax vaccine available in the United States. It’s composed of proteins derived from a bacterial culture.

Only specific groups of people can receive the anthrax vaccine, including groups like certain laboratory scientists, veterinarians, and military personnel. It can also be given to an unvaccinated person if they’re exposed to anthrax.

Most of the side effects from the anthrax vaccine are mild and go away after a few days. However, in rare cases, severe allergic reactions have occurred. If it’s recommended that you receive the anthrax vaccine, be sure to discuss the potential side effects with your doctor before receiving it.