Tetanus toxoid (TT)

Tetanus toxoid is an inactivated form of tetanus toxin that retains immunogenicity while eliminating toxicity. The original tetanus toxin is a 150 kDa protein composed of a 100 kDa heavy (B) chain and a 50 kDa light (A) chain connected by a disulfide bond[2][3]. The toxoid is created through a toxoiding process that modifies the protein structure to eliminate its toxic effects. Tetanus toxoid contains strong T-cell epitopes that make it an effective immunogen and carrier protein for conjugate vaccines[6]. However, the toxoiding process blocks many surface lysines, which can affect its conjugation capacity[6]. Additionally, tetanus toxoid is not a uniform product, as each manufacturer employs specific toxoiding and purification processes[6]. The native tetanus toxin functions by binding to gangliosides on neuronal membranes, undergoing internalization, and inhibiting neurotransmitter release by cleaving VAMP/synaptobrevin proteins[1][3][5]. The toxoid version maintains the immunogenic properties without the enzymatic activity that causes paralysis. As an alternative to traditional tetanus toxoid, recombinant tetanus toxin heavy chain fragment C (rTTHc) has been developed. This fragment contains the most immunogenic part of the toxin with the powerful T-cell epitopes but lacks the toxic enzymatic activity[6]. It offers the advantages of the toxoid with the reproducibility of a recombinant protein. Tetanus toxoid is a critical component of several vaccines, including the DPT (diphtheria, pertussis, tetanus) vaccine, and serves as a carrier protein in conjugate vaccines due to its strong immunogenic properties[6].

Other names

Tetanospasmin toxoidToxoided tetanus toxinTetanus vaccine component

Stimulates production of anti-tetanus antibodies Provides T-cell epitopes for conjugated antigens Induces protective immunity against tetanus toxin