Evaluation of previous patients who received doses of 40 or 80 mcg gp160 vaccine indicates that, although serum anti-gp160 antibody responses were detected, the level and duration of those responses were limited. A preliminary observation suggests that weak functional antibody responses may develop following the 18 month booster of 40 or 80 mcg; therefore, a dose of gp160 vaccine having potentially greater immunogenicity is of particular interest.
In the initial phase of the study, 20 healthy volunteers receive 640 mcg gp160 vaccine and 5 healthy volunteers receive alum placebo. At least 30 days later, 20 additional volunteers receive 1280 mcg gp160 vaccine and 5 volunteers receive placebo. Injections are given on days 0, 30, 180, and 365.
