Who Is Eligible for the Anthrax Vaccine?

Anthrax is usually an infection of the skin caused by specific bacteria that grow in soil. Anthrax is rare in humans and is more often found in cattle, sheep, and goats. People who work with these animals are at risk for infection and can benefit from vaccination.

This article discusses anthrax, its current vaccination recommendations, and the history of anthrax vaccination for military troops.

What Is Anthrax?

Anthrax is a rare disease caused by a bacteria called Bacillus anthracis that lives in the soil.

The disease usually affects animals, such as cattle, sheep, and goats, since they become infected when they breathe in or ingest spores from contaminated soil, plants, or water.

However, people can also become infected when exposed to spores from infected animals, wool, meat, or hides. A person cannot contract anthrax from another person like other illnesses such as a cold, the flu, or methicillin-resistant Staphylococcus aureus (MRSA).

Anthrax is rare in the United States, but sporadic outbreaks occur in wild and domesticated animals. Animal infections are more common in developing countries that do not have veterinary public health programs that routinely vaccinate animals against anthrax.

There are three major anthrax syndromes:

• Cutaneous: Anthrax affects the skin in people with open sores or cuts, usually on the face, neck, arms, and hands. This is the least dangerous form of anthrax and usually occurs 1-7 days after exposure. Anthrax in the skin starts with a small pimple that looks like an insect bite, and then it enlarges and changes into a painless ulcer. The ulcer develops a necrotic center that looks black from the dead skin.
• Inhalational: Anthrax can affect the lungs when people inhale bacterial spores. This is the most deadly form of anthrax. It usually develops about one week after exposure, but it can take up to two months for symptoms to start. The bacteria causes bleeding and fluid to build up in the lungs. Symptoms of inhalational anthrax include chest pain, shortness of breath, and, eventually, not being able to brethe. 
• Gastrointestinal: This form of anthrax is extremely rare. It occurs when people eat raw or undercooked meat from an infected animal. The infection usually starts approximately 1-7 days after exposure. Symptoms include nausea, bloody vomiting, diarrhea, abdominal pain, loss of appetite, and abdominal swelling. People can also have anthrax in the throat, leading to a sore throat, difficulty swallowing, and swelling in the neck.

Healthcare providers can treat anthrax with antibiotics if they diagnose it early. However, anthrax can be deadly, which is why people at high risk for the disease need to obtain an anthrax vaccine.

CDC Recommendations and High-Risk Groups

Anthrax vaccination is recommended for people between the ages of 18 and 65 years who are at risk for exposure to the bacteria. These people include:

• Laboratory workers who study and work with Bacillus anthracis 
• People who handle potentially infected animals
• Military personnel, who are determined by the Department of Defense (DOD) to be at high risk
• Some emergency and first responders who might be exposed to the bacteria
  

Anthrax vaccination is also recommended for unvaccinated people of all ages who have been exposed to the bacteria.

Anthrax Vaccine History

The anthrax vaccine was initially developed in the late 19th century and was a live nontoxic strain of Bacillus anthracis. In the 1930s, a live spore vaccine was created, and it remains in use for the vaccination of livestock in many parts of the world. This particular vaccine is credited with reducing the impact of anthrax on both animals and humans. 

Since then, inactivated anthrax vaccines have replaced live vaccines that were inappropriate for human use. The current vaccine is called anthrax vaccine adsorbed (AVA), or BioThrax. It was initially licensed in 1970.

The anthrax vaccine had undergone some manufacturing changes from the 1950s to the 1990s. Still, the vaccine was granted safety approval by the Food and Drug Administration (FDA) in 1970. It reaffirmed the vaccine's safety in 1985.

Anthrax Vaccine for the Military

At first, the anthrax vaccine was routinely given to a limited population of workers with a risk of exposure due to their interaction with livestock, wool, or animal hides.

However, during the Gulf War and later during the Iraq War, there were fears that U.S. military personnel would be at risk for infection from biological weapons. Approximately 150,000 troops received a dose of anthrax vaccine during the Gulf War, but the DOD did not require anthrax vaccination for soldiers until 1998. 

The DOD started the Anthrax Vaccine Immunization Program (AVIP) in 1998, intending to vaccinate all U.S. service members against anthrax. During the program’s initial years, vaccination efforts focused only on troops thought to be at the most significant risk for infection. A limited supply of vaccines until 2002 slowed program implementation.

Later, several military personnel grew concerned about the vaccine’s side effects. A survey conducted in 2000 by Congress’s General Accounting Office indicated that 85% of troops had some adverse reaction to the vaccine. At the same time, service members started to refuse the immunization or transferred their service location to avoid vaccination.

Anthrax Vaccine Ingredients

The anthrax vaccine does not contain any dead or live bacteria. A person cannot contract anthrax from the vaccine.

Each dose of the vaccine includes bacterial proteins and aluminum. The vaccine does not contain egg proteins or thimerosal, a mercury-containing preservative.

Anthrax Vaccine Schedule

Before Exposure

People at risk for anthrax exposure should be given five doses over a period of 18 months. People should obtain booster shots every year.

After Exposure

People exposed to anthrax should receive three doses over four weeks after exposure in conjunction with a 42-day course of antibiotics.

Anthrax Vaccine Side Effects

The side effects of the anthrax vaccine are similar to those of many other vaccinations, including:

• Tenderness in the arm at the vaccination site
• Headache
• Muscle aches
• Fatigue
• Dizziness

Researchers have not found a link between the anthrax vaccine and any long-term side effects.

Filing for Anthrax Vaccine Compensation

There has been much debate and confusion over the years on whether veterans qualify for disability after anthrax vaccination.

Veterans can apply for disability related to chronic symptoms from any vaccine received during service. However, there has not been a definite link found between anthrax vaccination and chronic health problems. At this time, chronic symptoms after anthrax vaccination do not readily qualify for compensation.

Summary

Anthrax infection is rare and typically involves the skin. Spores from the bacteria are found in the soil and more often infect animals, such as cattle, sheep, and goats. The anthrax vaccine was one of the first vaccines ever developed, and it has evolved to its current, inactive formulation.

The vaccine is recommended for people at risk for exposure to Bacillus anthracis bacteria or for those who have been exposed to it. Vaccination requires several doses and annual boosters. There is no proven link between specific symptoms and vaccination.

A Word From Verywell

Anthrax disease is extremely rare, and most people do not need a vaccine. However, anthrax in the lungs can be life-threatening. Therefore, people at risk for exposure to anthrax bacteria, including laboratory workers, animal handlers, certain military personnel, and first responders who may encounter a biological warfare event, should consider vaccination.

Speak with your employer about your risks for anthrax if it seems applicable, and then discuss vaccination with your healthcare provider.