Pfizer's vaccine for Clostridium difficile (C. diff) looks like it may join a growing list of candidates that have been shelved or delayed, after the shot failed to meet its primary objective in a ...

BT is produced by Clostridium botulinum and consists, of a complex mixture of proteins containing botulinum neurotoxin and various non-toxic proteins. Botulinum neurotoxin consists of a heavy chain ...