A Study to See Whether Two HIV Vaccines Are Safe and Can Prevent HIV Infection

This study consists of 2 parts:

Part A: Dose-escalation protocol using oligomeric gp160MN/LAI-2. Part B: Placebo-controlled, randomized, double-blind (within arm) study of vCP205 priming with gp160MN/LAI-2 boosting.

Volunteers are followed for at least 1 year.

Inclusion criteria

Volunteers may be eligible for this study if they:

• Are HIV-negative.
• Are in good health.
• Are between ages 18 and 55.
• Are available for at least 1 year.
• Are a resident of the United States of America.
• Agree to practice sexual abstinence or use birth control.

Exclusion criteria

Volunteers will not be eligible for this study if they:

• Have ever been given an HIV vaccine or certain other vaccines. (However, rabies vaccines are allowed.)
• Participate in activities that place them at high-risk for HIV infection, such as injection drug use or unprotected sex with someone who has HIV infection.
• Have certain psychiatric, medical, or substance abuse problems.
• Are allergic to eggs or other vaccines.
• Are an employee at a participating site and have access to study information.
• Are taking certain medications.
• Have received blood transfusions within 3 months before entering this study.
• Are pregnant or breast-feeding.