Studies on adjuvants for human prophylactics. I. Comparison of efficiencies of different adjuvants at various stages of immunization with tetanus and diphtheria toxoids.

Kinetic studies on the adjuvanticities of several substances with different modes of action were performed in guinea pigs by using tetanus and diphtheria toxoids as the antigens. When injected subcutaneously into animals, aluminium, endotoxin, pertussis vaccine and water in oil in water (w/o/w) showed very similar adjuvanticities to tetanus toxoid at the beginning stage of immunization, but the activities except that of aluminium became less significant at later stages after the primary stimulus when antitoxin was produced abundantly. Poly L-lysine and to a less extent poly A:U showed potent adjuvanticities next to that of aluminium throughout the whole immunization period. Combination of poly L-lysine with 0.03 mg aluminium showed a similar adjuvanticity to that of 0.9 mg of aluminium alone. In contrast to rather low adjuvanticities to tetanus toxoid, more distinct adjuvanticities were observed to diphtheria toxoid throughout the whole period of immunization with various substances such as aluminium, poly A:U, w/o/w and poly L-lysine but not with endotoxin.