Anthrax is an infectious disease caused by bacteria that can
survive for years as spores. It is usually found in animals,
such as cattle, sheep, and goats. Although human cases are
uncommon in the United States, people can get anthrax by
inhaling spores from infected animals or animal products.
Anthrax leads to breathing problems, serious illness, and often
death. In 2001, anthrax spores were deliberately spread through
the U.S. mail. The release of a large amount of anthrax spores
into the air could harm many people, so terrorists could use
anthrax in an attack. It is uncertain what would be the best way
to protect people in such an attack. Antibiotics can help reduce
serious anthrax illness, but they must be given early because
the disease worsens rapidly. A vaccine for anthrax is available,
but public health officials are reluctant to vaccinate the
general population because of the vaccine's side effects and
costs.