Importance of (antibody-dependent) complement-mediated serum killing in protection against Bordetella pertussis

Pertussis is a highly contagious respiratory disease that is caused by Bordetella pertussis. Despite being vaccine preventable, pertussis rates have been rising steadily over the last decades, even in areas with high vaccine uptake. Recently, experiments with infant baboons indicated that although vaccination with acellular pertussis vaccines prevented disease, no apparent effect was observed on infection and transmission. One explanation may be that current acellular pertussis vaccines do not induce high levels of opsonophagocytic and/or bactericidal activity, implying that engineering of vaccines that promote bacterial killing may improve efficacy. Here, we discuss the importance of complement-mediated killing in vaccine-induced protection against B. pertussis. We first examine how B. pertussis may have evolved different complement evasion strategies. Second, we explore the benefits of opsonophagocytic and/or bactericidal killing in vaccine-induced protection and discuss whether or not inclusion of new opsonophagocytic or bactericidal target antigens in pertussis vaccines may benefit efficacy.