toxoid

A toxoid is a weakened or inactivated form of a toxin produced by bacteria. It retains the ability to stimulate the immune system to recognize and respond to the toxin, but it doesn’t cause illness. Toxoids are used in vaccines to help the body build immunity against bacterial diseases, such as tetanus and diphtheria. By introducing these harmless versions, the immune system learns to defend against the real toxins should they ever be encountered, providing protection without causing the disease itself.