Anthrax itself is an acute disease caused by the bacterium Bacillus anthracis. Most forms of the disease are lethal, and it affects both humans and other animals.
Like many other members of the genus Bacillus, Anthrax can form dormant endospores that are able to survive in harsh conditions for decades or even centuries. When the spores are inhaled, ingested, or come into contact with a skin lesion on a host they may reactivate and multiply rapidly.
Anthrax appears in Fallout 2.