Studies in Immunization

Rabbits immunized with BSA-rabbit anti-BSA specific precipitates combined with Freund's complete adjuvant produced circulating antibody and delayed hypersensitivity to the BSA portion of the complex. Rabbits immunized with specific precipitates given intravenously produced antibody to the BSA portion when the complex was formed at equivalence but not when the complex was formed in antibody excess. An additional antibody produced by some rabbits was shown to be directed towards the rabbit γ-globulin portion of the complex. No antibody was found which could be considered specific for the particular complex used for immunization.