In 1923, it was discovered that treatment with formalin eliminated the toxicity of diphtheria toxin (DT) without destroying its immunogenicity. Formalinâ€treated DT, now called diphtheria toxoid, rapidly became the preferred vaccine against diphtheria, and diphtheria toxoid (usually in combined vaccines, such as diphtheriaâ€tetanus toxoids–pertussis vaccine [DTP] or diphtheriaâ€tetanus toxoids–acellular pertussis vaccine [DTaP] for children and tetanusâ€diphtheria toxoids vaccine for adults [Td]) is still used throughout the world for active immunization against diphtheria (Holmes, 2000).
References
Holmes, 2000: Holmes RK. Biology and molecular epidemiology of diphtheria toxin and the tox gene. The Journal of infectious diseases. 2000; 181 Suppl 1; S156-167. [PubMed: 10657208].
