Immunostimulating Complex (ISCOM)

For almost two centuries vaccines have been based on whole micro-organisms, killed (inactivated) or attenuated. With increasing knowledge of the molecular composition of pathogenic micro-organisms and the function of different molecules, protective antigens also became identified. In spite of the fact that some of the early killed whole micro-organism vaccines proved to be effective there are several reasons why vaccines in the future should be formulated based on defined antigens, e.g.: (i) To avoid hazards due to toxicity or to genetic material which may cause replication, or as regards retroviruses the integration of viral genes into the infected hostcell genome. (ii) To limit the number of antigens in a vaccine in order to decrease the risk for induction autoimmune or allergic reactions. (iii) Further, reorganization of the prospective protective antigens may break a strategy for survival of the pathogen in the “hostile” immunological environment of the infected host.