Gene therapy and viral vaccination: the interface.

Live viral vaccines have had a major impact on the incidence of acute virus infections world-wide. Virus infections recognised as future vaccine targets will require a modified approach based on a detailed understanding of the immunobiology of specific infections combined with the application of new technologies designed to generate specific and appropriate protective immunity. A similar vector technology directed at in vivo gene delivery is currently being exploited both for gene therapy and vaccination. The induction of an immune response to an expressed transgene represents a potential hazard for a gene therapy protocol but is the object of a vaccine strategy. In vivo gene delivery using replication-competent or replication-deficient viral vector systems and by direct transfer of naked DNA can generate an effective humoral, secretory and cell-mediated immune response to expressed transgenes.