Do early childhood immunizations influence the development of atopy and do they cause allergic reactions?
Concerns about allergic side-effects of vaccines and about a possible promotion of allergic diseases contribute to incomplete vaccination rates in childhood. This article reviews the current understanding of these issues. There is evidence that pertussis and diphtheria/tetanus antigens elicit immunoglobulin E (IgE) antibody formation as part of the immune response. In murine models, pertussis toxin is an effective adjuvant for IgE formation against simultaneously administered antigens. In children, however, sensitization to unrelated antigens or development of allergic diseases do not seem to be augmented. In contrast, bacille Calmette-Guérin (BCG) and measles vaccination have been proposed as suppressors of allergy because of their T helper 1 (Th1)-fostering properties. In the murine system, BCG inhibits allergic sensitization and airway hyper-reactivity. Some epidemiological studies in humans suggest an inhibitory effect of tuberculosis on allergy. BCG vaccination in children, howeve