Once common where livestock were raised, it is now controlled through animal vaccination programs. Anthrax still occurs in countries where animals are not vaccinated, mainly in Africa and Asia. It does occur infrequently in other countries, including the United States. Human infection with anthrax usually results from direct contact with infected animals, or animal products such as wool, meat or hides. However, when anthrax is used as a biological weapon, people become infected by breathing anthrax spores that are released into the air.
Inhalation anthrax is the disease that results from breathing anthrax spores.
Symptoms of inhalation anthrax can begin as early as 24 hours after breathing the spores. Vaccines prevent illness by stimulating the body's natural disease-fighting abilities. They are among the most powerful tools developed by modern medicine for keeping people healthy. Vaccines are routinely used in the United States to protect against diseases such as mumps, measles, whooping cough and polio. As part of force protection, military personnel are given additional vaccines to protect against naturally occurring diseases encountered when deploying overseas, such as typhoid, hepatitis and yellow fever.