Development of immunologic memory against tetanus toxoid and pertactin antigens from the diphtheria-tetanus-pertussis vaccine in atopic versus nonatopic children

Background: Recent findings suggest that a hallmark of the atopic phenotype is reduced capacity to respond to vaccine antigens, as well as to environm ental allergens, during infancy. This deficiency, which is most marked for the cytokine IFN-gamma, appears transient but can result in a long-lasting imbalance within T helper cell (T-H) memory responses to allergens. Indirec t evidence suggests that parallel effects may occur within immunologic memo ry responses against vaccine antigens in atopic children. Objective: Our purpose was to compare vaccine antigen-specific T-H memory r esponses in atopic and nonatopic children. Methods: We analyzed specific serum IgG and cytokine responses to pertactin and tetanus antigens as well as to mitogen (PHA) and house dust mite (HDM) allergen in 25 HDM-sensitized atopic and 25 nonatopic 6-year-old children who were vaccinated and boosted with diphtheria-tetanus-pertussis (DTP) vac cine. Results: PBMCs from the atopic subjects produced higher levels of T(H)1 and T(H)2 cytokines to HDM allergen and PHA. Vaccine antibody titers were norm al in the atopic subjects; vaccine-specific T(H)2 responses were rarely det ectable, yet T(H)1 (IFN-gamma) responses, in particular against tetanus, we re frequent and higher in the atopic subjects (121.5 [SE 64.3] vs 8.0 [3.5] pg/mL culture fluid, P = .04). Corresponding pertactin responses were comp arable in both groups. Conclusions: At the completion of the full primer-booster DTP vaccination r egimen, levels of vaccine-specific immunity in atopic 6-year-old children a re at least equivalent to their nonatopic counterparts, indicating that the transient atopy-associated deficiency in T(H)1 function in childhood can b e successfully overcome by appropriate vaccination and boosting regimens.