Anthrax is caused by bacteria that are usually found in animals but can spread to humans as well. There are a number of different forms of human anthrax, including cutaneous anthrax, which involves the skin, and inhalational anthrax, which involves the lungs. The average fatality rate is over 20 percent if the anthrax is untreated. In some severe cases, the fatality rate is near 100 percent, even with appropriate antibiotics.
Anthrax was in the news in 2001, when letters with anthrax bacteria were mailed to several news media offices and to two United States senators. These attacks infected over twenty people, and five ultimately died of their infection.
The anthrax vaccine is primarily given to military personnel and researchers or lab workers who work directly with the bacteria. In certain circumstances, veterinarians who work overseas or people who work with imported animal furs or hides might also be vaccinated. The basic vaccine series is a set of five vaccines at zero and four weeks, then at six, twelve, and eighteen months. In addition, there is a recommended booster every year after the initial series to maintain the protection from the disease. Over 95 percent of recipients develop antibodies to anthrax bacteria after three doses.
The mild side effects of the anthrax vaccine include soreness, redness, and itching, as well as a lump at the location of the injection. Other recipients may experience fevers, chills, nausea, headaches, muscle aches, and general malaise. These mild side effects usually go away on their own.
A moderate side effect listed on the anthrax Vaccine Information Sheet is a large area of redness at the location of the injection in 5 percent of recipients. A severe allergic reaction to the vaccine occurs in fewer than one in every one hundred thousand recipients.
The anthrax vaccine should not be given to anyone who has had a severe allergic reaction to a previous dose of the vaccine or to any component in the vaccine. The vaccine should also not be given to anyone who has survived a past exposure to anthrax, such as cutaneous anthrax. The vaccine is not recommended for women who are pregnant but can be given if there is a high risk of exposure to anthrax. People who are moderately or severely ill should be cautioned against receiving this vaccine until they recover from their illness.