Assessment of humoral and cell-mediated immunity against Bordetella pertussis in adolescent, adult, and senior subjects in Italy

SUMMARYHumoral and cell-mediated immunity (CMI) againstB. pertussiswas assessed in a sample of adolescent, adult and senior subjects distributed in five different geographical areas in Italy. Most (99·1%) subjects had IgG anti-pertussis toxin (PT) antibodies exceeding the minimum detection level [⩾2 ELISA units (EU)/ml]. There were no significant differences between the genders; 6·2% samples recorded titres ⩾100 EU/ml. CMI was positive [stimulation index (SI) ⩾5] against PT in 39·0% of all samples. This study suggests thatB. pertussiscontinues to circulate in age groups that have been previously considered to be uninvolved in the circulation of this pathogen and that adolescent and adult pe…