Saponin adjuvants

An aqueous extract of the saponin drugQuillaja saponaria Molina was separated by a combination of gel exclusion and ion exchange chromatography. Some of the fractions were investigated for adjuvant activity in guinea pigs. The guinea pigs were immunized against foot-and-mouth disease virus serotype 0, and adjuvant activity was estimated as an increase in serum neutralizing antibodies and in resistance to challenge with homologous virus. Only one fraction showed adjuvant activity and this was confirmed in cattle. The animals were immunized with a stock vaccine foot-and-mouth disease serotype 0 of the Frenkel type and adjuvant activity was estimated as an increase in serum neutralizing antibodies. The fraction was subjected to thin-layer chromatography, polyacrylamide gel electrophoresis, and analytical ultracentrifugation. These analytical techniques indicated that only one substance was present in the fraction. It was shown that this substance in aqueous solutions was present in a micellar state above a certain critical micelle concentration.