Tetanus toxin (TT) is a very potent neurotoxin generated by the vegetative cells of Clostridium tetani that can lead to tetanus. Detoxified tetanus toxin has been approved as a toxoid vaccine for the prevention of diphtheria.
Tetanus toxin (TT), diphtheria toxin, and CRM197 are typical carrier proteins provided for the polysaccharide conjugate vaccines.
The two FDA-approved Haemophilus b conjugate vaccines, ActHIB (Sanofi) and HIBERIX (GlaxoSmithKline), are based on detoxified tetanus toxin. PedvaxHIB (Merck Sharp & Dohme) is linked with the Meningococcal outer membrane protein complex (OMPC). The vaccine is approved as a Haemophilus b conjugate vaccine.
Developed by Sanofi, MenQuadfi is a tetanus toxoid conjugate vaccine against Meningococci (A, C, Y, and W). Additional meningococcal ACYW vaccines Menveo (GlaxoSmithKline) and Menactra (Sanofi) are based on the CRM197 carrier protein and inactivated diphtheria toxin, respectively.
In addition, novel carrier proteins derived from tetanus toxoid, such as native tetanus toxin fragment C (TTFc) manufactured in bacteria (Escherichia coli), yeast (Saccharomyces cerevisiae and Pichia pastoris), or other hosts using recombinant DNA technology, are currently under investigation.