Bacillus anthracis is an aerobic, spore-forming bacterium that causes anthrax disease. Anthrax occurs globally, especially in agricultural areas that do not have a livestock vaccination program. Naturally occurring anthrax is rare in the United States, which has successful vaccination programs among livestock and strict importation regulations. In 2001, anthrax bacteria were used in bioterrorism attacks involving the postal system and government buildings. Regardless of the cause, all suspected cases of anthrax must be reported to the local health department for investigation.
Anthrax bacteria infect people and animals when spores are inhaled, ingested, or enter the body through a break in the skin. Once inside the body, the spores replicate and produce three proteins: edema factor (EF), lethal factor (LF), and protective antigen (PA). It is the combination of these proteins that is believed to cause tissue damage, shock, and death. Sometimes there is a delayed onset of anthrax disease. This is because anthrax spores can remain in the lungs for weeks without replicating. Antibiotics do not kill the spores. When the spores finally do replicate, anthrax disease develops.
There are three forms of anthrax disease:
Antibiotics, such as ciprofloxacin, doxycycline, and amoxicillin, are the most important therapeutic interventions for any form of anthrax. A combination of antibiotics needs to be started as soon as the disease is suspected. In addition, aggressive supportive care will be needed.
In 1991, DoD Service members deploying for the Persian Gulf War received one or two doses of anthrax vaccine, labeled Vaccine A or Vacc A. Other abbreviations for anthrax vaccine include AVA and ANT. Before November 2008, the vaccine was given as a 6-dose series. Research on the vaccine showed, however, that five doses are as effective as six doses in preventing anthrax. So, in November 2008, the primary series of anthrax vaccine was changed to five doses. See "Dose/Schedule" for more information.
Product: Biothrax® (Anthrax Vaccine Adsorbed)
Manufacturer: Emergent BioDefense Operations Lansing Inc
Year licensed: 1970
Pregnant women who have received the anthrax vaccine during pregnancy should receive regular prenatal care and should discuss their anthrax vaccination with their healthcare provider and/or obstetrician. IHB has the latest information regarding pregnancy and vaccination, as well as adverse event research. IHB also offers pregnancy monitoring for women inadvertently vaccinated during pregnancy. For more information, please visit the Pregnancy page or contact IHB.
In April 2000, the research project published its first peer-reviewed report, describing an enzyme-linked immunosorbent assay (ELISA) that could detect antibodies to squalene induced in mice. Use of squalene alone did not produce a significant amount of anti-squalene antibodies. A special chemical was needed to induce the antibodies against squalene in mice. After injecting mice with liposomes (fat globules) containing 71% squalene (710 million parts per billion), plus a second chemical called lipid A, antibodies to squalene were readily induced in mice. The validity of the method was established using positive and negative controls to preclude false positive and false-negative test results. The investigators concluded that squalene is a weak antigen (a weak inducer of antibodies). (Matyas et al., 2000).
By September 2001, researchers reported improving the assay and ensuring these tests were reproducible and sensitive enough to detect 80 ng/ml of anti-squalene antibody. The test was also reproducible from experiment to experiment (Matyas et al., 2001). The third study from this research effort, published in 2004, adapts the test described above so that it could detect anti-squalene antibodies if present in human serum. Serum from three groups of people were tested: retired employees of the U.S. Army Medical Research Institute of Infectious Diseases (average 68 years of age, 88% of whom received anthrax vaccine, mean = 26 doses per person) , civilian volunteers of similar age from Frederick, Maryland (none of whom received anthrax vaccine), and random blood donors from Fort Knox, Kentucky (vaccination status unknown), This next study indicates that anti-squalene antibodies are found in 7.5% of the vaccinated USAMRIID alumni, 15% of the unvaccinated Frederick civilians, and in 0% of the Fort Knox blood donors. The antibodies described in the previous sentence were a type of antibody called IgG. Researchers found another type of anti-squalene antibody called IgM in all three groups (37%, 32%, and 19%). The researchers found that anti-squalene antibodies are more common with increasing age (a characteristic also found in mice). The presence of anti-squalene antibodies was unrelated to anthrax vaccination status. They concluded that anti-squalene antibodies occur naturally in humans (Matyas et al., 2004).