Recent animal studies indicate that immunizing with MN rsgp120/HIV-1 in combination with QS21 on a 0, 1, 2 month schedule results in a more rapid rise in binding and neutralizing antibody response than on a 0, 1, 6 month schedule. Such an effect may be particularly desirable in vaccine delivery. This study compares these two delivery schedules using the unadjuvanted vaccine formulation rsgp120/HIV-1 with or without addition of alum.~Healthy volunteers (20 per group) receive MN rsgp120/HIV-1 (300 or 0 mcg) in combination with QS21 (100 mcg), either with or without alum, at 0, 1, and 2 months or 0, 1, and 6 months. For both vaccination schedules, an additional five volunteers receive only vehicle with alum. The 0 mcg antigen groups are included primarily as negative controls. Subjects may be contacted for follow-up on health status once or twice yearly for at least 5 years.
To extend the evaluation of safety and immunogenicity of MN recombinant soluble gp120/HIV-1 (MN rsgp120/HIV-1) in combination with QS21 with or without alum and on two different vaccination schedules.~Recent animal studies indicate that immunizing with MN rsgp120/HIV-1 in combination with QS21 on a 0, 1, 2 month schedule results in a more rapid rise in binding and neutralizing antibody response than on a 0, 1, 6 month schedule. Such an effect may be particularly desirable in vaccine delivery. This study compares these two delivery schedules using the unadjuvanted vaccine formulation rsgp120/HIV-1 with or without addition of alum.