Antitoxin

Antitoxin, antibody released into the bloodstream to counteract the poisonous products (toxins) of invading bacteria. When a small amount of a bacterial toxin is injected into the blood, the body produces its own antitoxins to combat infection. The body may also accept blood serum injected from another organism that has already formed the antitoxin. This technique is effective in fighting such diseases as diphtheria and tetanus.