FIG. 3.

ELISA antibody response to disrupted FIV antigen in FIV-RBC-immunized and control cats. Solid symbols indicate individual FIV-RBC-immunized animals. A single open symbol is used for BSA-RBC-immunized cats, as they were all unreactive. The arrows indicate the times when immunizing doses were administered, and the solid arrowheads indicate the times of challenge. (A) Response to primary immunization. (B) Response to a booster FIV-RBC dose given 20 months after completion of the primary immunization.