Studies about the adjuvant activity of saponin fractions in foot and mouth disease vaccine. III. Comparison of the irritant, adjuvant and hemolytic activities of six commercial saponins and their hemolytic fractions obtained by chromatography on sephadex G 100.

12 experimental vaccines were prepared to compare the irritant and adjuvant activity in cattle of 6 commercial saponin preparations and their hemolytic fractions. It is still not known if a single substance is responsible for the irritant, adjuvant and hemolytic activities of the saponin preparations. The quantities of saponin added were standardised on the base of a constant hemolytic activity rather than on a weight of powder per dose of vaccine base. A FMD vaccine was used to reveal the adjuvant activity. It was concluded that the irritation is related to the hemolytic activity and not to the weight of powder. Irritation is slightly reduced when a toxic effect appears. The adjuvant activity was higher for untreated saponin preparations with high hemolytic activity used at low dose and for one of the chromatographic saponin fractions. The adjuvant activity is reduced when toxic effect appear. Toxicity of less hemolytic saponins used at high dose is removed by chromatography. Highly hemolytic saponins used at low dose become toxic after chromatographic treatment.