IMMUNOPOTENTIATION AND DELIVERY SYSTEMS FOR ANTIGENS FOR SINGLE-STEP IMMUNIZATION - RECENT TRENDS AND PROGRESS

The use of adjuvants for immunopotentiation has been investigated sinc e the 1920s and a number of comprehensive reviews and monographs have been published on this subject. A recent trend in immunopotentiation h as been the use of delivery systems which allow for sustained or contr olled release of antigens and which induce prolonged immunity followin g a single dose. This concept has been termed either single-step or si ngle-shot immunization. The delivery system has been modulated to pote ntiate the immune response either by delivering the antigen (and perha ps an adjuvant or adjuvants) either over a prolonged period of time or in a predetermined sequence or by incorporating substances with immun oadjuvant properties (e.g., lecithin and certain biodegradable polymer s) as carriers within the delivery system. This Review focuses on the progress made in the design of delivery systems for immunopotentiation . Particular emphasis is given to delivery systems designed to achieve single-step immunization.