Inclusion Criteria

Patients must have or be:

• Healthy.
• Negative ELISA for HIV.
• Negative for Hepatitis B surface antigen.
• Normal urine dipstick.
• Normal history and physical exam.
• Availability for follow-up for planned duration of the study (60 weeks).

Risk Behavior: Required:

• Lower or intermediate risk sexual behavior as defined by AVEG.

Exclusion Criteria

Co-existing Condition:

Patients with any of the following symptoms or conditions are excluded:

• Medical or psychiatric condition or occupational responsibilities which preclude subject compliance with the protocol.
• Active syphilis. NOTE: If the serology is documented to be a false positive or due to a remote (> 6 months) treated infection, the volunteer is eligible.
• Active tuberculosis. NOTE: Volunteers with a positive PPD and a normal chest X-ray showing no evidence of TB and not requiring INH therapy are eligible.

Patients with any of the following prior conditions are excluded:

• History of immunodeficiency, chronic illness, malignancy or autoimmune disease.
• History of anaphylaxis or other serious adverse reactions to vaccines.
• History of inflammatory gastrointestinal disease, celiac disease or intestinal malignancy.
• History of acute gastroenteritis within the past month or gastrointestinal surgery within the past 12 months.

Prior Medication:

Excluded:

• History of use of immunosuppressive medication.
• Live attenuated vaccines within 60 days of study. NOTE: Medically indicated subunit or killed vaccines (e.g., influenza, pneumococcal) are not exclusionary but should be given at least 2 weeks away from HIV immunizations.
• Use of experimental agents within 30 days prior to study.
• Receipt of blood products or immunoglobulin in the past 6 months.
• Prior receipt of HIV vaccines or a placebo recipient in an HIV vaccine trial.

Risk Behavior:

Excluded:

• Subjects with identifiable higher risk behavior for HIV infection as determined by screening questionnaire designed to identify risk factors for HIV infection.
• History of injection drug use within the last 12 months to enrollment.
• Higher risk sexual behavior as defined by AVEG.