DISTINCT T-CELL SUBTYPES INDUCED WITH WHOLE-CELL AND ACELLULAR PERTUSSIS VACCINES IN CHILDREN

Recent clinical trials have demonstrated that new generation acellular pertussis vaccines can confer protection against whooping cough. Howe ver, the mechanism of protective immunity against Bordetella pertussis infection induced by vaccination remains to be defined. We have exami ned cellular immune responses in children immunized with a range of ac ellular and whole cell pertussis vaccines. Immunization of children wi th a potent whole-cell vaccine induced B. pertussis-specific T cells t hat secreted interferon-gamma (IFN-gamma), but not interleukin-5 (IL-5 ). In contrast, T cells from children immunized with acellular pertuss is vaccines secreted IFN-gamma and/or IL-5 following stimulation with B. pertussis antigens in vitro. These observations suggest that protec tive immunity conferred by whole-cell vaccines, like natural immunity, is mediated by type 1 T cells, whereas the mechanism of immune protec tion generated with acellular vaccines may be more heterogenous, invol ving T cells that secreted type 1 and type 2 cytokines.