Airborne anthrax is the worst form. People cannot smell, see, or taste anthrax contamination in air, but almost all people who inhale it will die within about one week. Rarely will a person know of exposure before any symptoms appear, and then antibiotic treatment is likely too late to be effective. The deadliness of airborne anthrax is only one reason it could be such an effective biological weapon. The bacteria can survive for decades because they form a protective coating called a spore, which allows them to live 40 years or more in various environmental conditions.
Airborne distribution can easily spread anthrax spores over large areas.
Fortunately, we have effective defenses against this deadly weapon of potential mass destruction. The Food and Drug Administration has licensed an anthrax vaccine available in the U.S. for almost 30 years. Thereafter, yearly boosters maintain immunity. The shot may cause a burning sensation at the injection site, but this usually dissipates in a few minutes. The Coast Guard is phasing in its vaccination program.