Anthrax is a soil bacterium that produces a disease deadly to animals. A herd of cattle exposed to anthrax is usually slaughtered to keep it from spreading. Anthrax spores can live in the soil for up to fifty years.
The most common form in humans is cutaneous anthrax, where the bacterium enters through a break in the skin.
During an infection, an initial skin lesion forms then blisters. The blister breaks down into a black ulcer and nearby lymph nodes may become infected and painful. A scar is often formed which then dries and falls off within two weeks. In 20% of untreated individuals, the infection may spread to the bloodstream and become fatal.
Antibiotics are a big help in controlling and curing anthrax.
It has been said that no controlled, double-blind studies have been done of various vaccines. But there are still results. Here’s the entry for anthrax vaccine, from the UK Department of Health’s ‘s Green Book:
The vaccine is made from antigens found in the sterile filtrate from cultures of the Sterne strain of B. anthracis. These antigens are adsorbed onto an aluminium adjuvant to improve their immunogenicity and are preserved with thiomersal. The vaccine is inactivated, does not contain live organisms and cannot cause the disease against which it protects.
There have been no formal efficacy trials with the UK vaccine. In 1958, the introduction of vaccine successfully controlled cutaneous anthrax at a government wool-disinfecting station in Liverpool (Hambleton et al., 1984). A controlled clinical trial was carried out in the 1950s among workers in goat-hair mills in New Hampshire, USA, using a vaccine similar to that currently licensed in the USA and the UK (Brachman et al., 1962). Although the study did not have sufficient power to accurately measure protection against pulmonary anthrax, no cases occurred in the vaccinated group compared with five in the unvaccinated.
There have been no recorded cases of anthrax infection in individuals vaccinated in the UK.