Saponin adjuvants. VI. The adjuvant activity of quil A in trivalent vaccination of cattle and guinea pigs against foot-and-mouth disease.

The saponin adjuvant Quil A was investigated in trivalent vaccination against foot-and-mouth disease with a concentrated vaccine based on BHK suspension cell virus of the serotypes O, A and G. The activity in cattle was estimated on the basis of seroneutra-lizing antibodies. Five and 10 ml doses with or without 1 mg of Quil A were each injected into 6 animals. Seroneutralizing antibodies were estimated at regular intervals during a period of 29 weeks. The activity in guinea pigs was estimated by experimental challenge. One ml doses of serial 4-fold dilutions of the vaccine with or without 50 µg of Quil A were injected into 24 groups of 20 guinea pigs. Challenge was given 3 weeks after vaccination. It was concluded that Quil A showed adjuvant activity in cattle and guinea pigs with all the serotypes used in the trivalent vaccination.