toxoid, protein toxin treated by heat or chemicals so that its poisonous property is destroyed but its capacity to stimulate the formation of toxin antibodies, or antitoxins, remains. Because toxoids can be given in large quantities with no risk of tissue damage, they have superseded the highly poisonous toxins as immunizing agents against such diseases as diphtheria and tetanus.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.