SETBP1 and pertussis: This is in good agreement with previous studies showing that nonvirulent mutant toxins were immunogenic in animals and humans, e.g., a licensed acellular pertussis vaccine [41], a recombinant toxoid vaccine against Clostridium difficile [42], a recombinant Clostridium perfringens epsilon toxin mutant vaccine [43], and a mutant recombinant SEB vaccine [44].