In autumn of 2001,anthrax and the anthrax vaccine became prominent national concerns.Deliberate distribution through the mail of spores of the bacteria that cause anthrax resulted in at least five deaths and 13 non-fatal infections,and thousands of people receiving treatment for known or suspected exposure to the spores.Along with the entire nation,public health and health care professionals found themselves facing many new questions about the disease,its treatment,and its prevention.