clostridium difficile toxoid vaccine

ACAM-CDIFF is a toxoid-based vaccine candidate originally developed by Acambis and later by Sanofi Pasteur for the prevention of *Clostridium difficile* infection (CDI). The vaccine is composed of inactivated toxins (toxoids) A and B derived from *C. difficile*. Its mechanism of action involves stimulating the host's immune system to produce neutralizing IgG antibodies against Toxin A (TcdA) and Toxin B (TcdB), which are the primary virulence factors responsible for the diarrhea and mucosal damage associated with CDI. By neutralizing these toxins, the vaccine aims to prevent the clinical manifestations of the infection rather than the colonization of the bacteria itself. Although the program reached Phase 3 clinical trials (the Cdiffense study), Sanofi discontinued its development in 2017 after an interim analysis indicated that the trial was unlikely to meet its primary efficacy endpoint in preventing primary CDI.

Other names

clostridium difficile toxoids a and bC. difficile toxoid vaccineSanofi C. difficile vaccine