Delivery can be achieved by contacting the dendritic cells with a virosome ex vivo, whereupon the infected dendritic cells are provided to the patient. At other times, delivery may be achieved by delivering the virus to the subject in order to infect dendritic cells in vivo. The dendritic cells then stimulate antigen-specific T cells or B cells in the patient to induce cellular and humoral immune responses to the expressed antigen. In this manner, a patient suffering from a disease or disorder is treated by generating immune cells with the desired specificity.