A large attack on a major metropolitan area with airborne anthrax could affect more than a million people, necessitating their treatment with powerful antibiotics. A new study finds that in order for a response to be effective, quick detection and treatment are essential, and any delay beyond three days would overwhelm hospitals with critically ill people.

University of Florida researchers have revealed how the inhaled form of anthrax paralyzes the body's defenses and prevents immune cells from reaching the site of infection.