Cell-mediated immunity and antibody responses to Bordetella pertussis antigens in children with a history of pertussis infection and in recipients ofan acellular pertussis vaccine

Cell-mediated immunity (CMI) and antibody responses to Bordetella pertussis antigens were assessed 4-6 years after primary infant immunization with di phtheria-tetanus tricomponent acellular pertussis (DTaP) or diphtheria-teta nus (DT) vaccine in a country with high endemicity of B. pertussis infectio n. CMI to the B. pertussis antigens (especially to the pertussis toxin [PT] ) was more frequent and/or intense in DTaP than in DT recipients. No lympho proliferation differences were found between those with and without a histo ry of pertussis although the DT recipients produced very Little interferon- gamma after antigen (particularly PT and filamentous hemagglutinin [FHA]) s timulation. In contrast, seropositivity to PT, but not to pertactin or FHA was more frequent in DT recipients with history of pertussis than in all ot her subjects, Thus, years after disease or vaccination, CMI response to PT or circulating PT antibodies appears to be the main distinctive feature of pertussis-protected DTaP recipients or pertussis-affected DT recipients.