Part A: To evaluate the safety and immunogenicity of ALVAC vCP125 HIV-1 gp160 MN live canarypox recombinant vaccine (ALVAC gp160 MN) versus a recombinant canarypox expressing the rabies glycoprotein (ALVAC rabies glycoprotein) as a control in healthy, HIV-1 uninfected adult volunteers.

Part B: To evaluate the schedule of two immunizations with ALVAC gp160 MN for optimal immunogenicity.

Amendment: 12/22/93: To determine whether ALVAC gp160 MN in combination with SF-2 rgp120 subunit protein is capable of generating humoral and cellular immune responses of greater intensity and longer duration than either vaccine administered alone.

A canarypox-vectored vaccine (ALVAC) that expresses the gp160 antigen of the HIV-1 MN strain might satisfy many criteria for an affordable HIV vaccine. Per 12/22/93 amendment: Cellular responses have been augmented by the combination of two recombinant vaccines, especially in vaccinia naive individuals.

A canarypox-vectored vaccine (ALVAC) that expresses the gp160 antigen of the HIV-1 MN strain might satisfy many criteria for an affordable HIV vaccine. Per 12/22/93 amendment: Cellular responses have been augmented by the combination of two recombinant vaccines, especially in vaccinia naive individuals.

In Part A, 28 healthy volunteers (15 vaccinia-immune and 13 vaccinia-naive) are randomized to receive intramuscular injections of ALVAC gp160 MN at a dose of 1 million TCID50 or ALVAC rabies glycoprotein as a control at months 0 and 2. In Part B, 90 healthy volunteers (60 vaccinia immune and 30 vaccinia naive) are randomized to receive ALVAC gp160 MN at a dose of 10 million TCID50 or ALVAC rabies glycoprotein control, on an immunization schedule of either month 0 and 1 or 0 and 2. For Part B, half of the patients receiving ALVAC gp160 MN, as well as approximately half of those receiving control vaccine, will receive booster immunizations with SF-2 rgp120 subunit protein, if available, at months 9 and 12; the other half will receive booster immunizations with the same preparation as they received for their first two immunizations. In Part A, all control volunteers except one within each control group receive SF-2 rgp120 subunit protein at months 9 and 12. An additional group of 10 volunteers will receive four injections of SF-2 rgp120 subunit protein at months 0, 1, 6 and 12. Part B will begin whenever the higher dose of ALVAC gp160 MN becomes available (at least 4 weeks after initiation of Part A). Volunteers are followed for at least 18 months. Per 06/10/94 addendum, volunteers will be contacted once or twice per year for at least 5 years to check on health status.

Inclusion Criteria

Subjects must have:

• Normal history and physical exam.
• Negative ELISA for HIV.
• CD4 count >= 400 cells/mm3.
• Normal urine dipstick with esterase and nitrite.
• Lower risk sexual behavior.

NOTE:

• No more than 10 percent of participants will be older than 50 years.

Prior Medication:

Allowed:

• Prior smallpox vaccination.

Exclusion Criteria

Co-existing Condition:

Subjects with the following symptoms or conditions are excluded:

• Positive hepatitis B surface antigen.
• Medical or psychiatric condition (such as recent suicidal ideation or present psychosis) that precludes compliance.
• Occupational responsibilities that preclude compliance.
• Active syphilis. NOTE: Subjects with serology documented to be a false positive or due to a remote (> 6 months) treated infection are eligible.
• Active tuberculosis. NOTE: Subjects with a positive PPD and a normal chest x-ray showing no evidence of TB and not requiring isoniazid therapy are eligible.
• Allergy to egg products or neomycin.
• Occupational exposure to birds.

Subjects with the following prior conditions are excluded:

• History of immunodeficiency, chronic illness, autoimmune disease, or use of immunosuppressive medications.
• History of anaphylaxis or other serious adverse reactions to vaccines.
• Prior immunization against rabies.
• History of serious allergic reaction to any substance, requiring hospitalization or emergent medical care (e.g., Stevens-Johnson syndrome, bronchospasm, or hypotension).
• Prior psychiatric condition (such as history of suicide attempts or past psychosis) that precludes compliance.
• History of cancer unless there has been surgical excision that is considered to have achieved cure.

Prior Medication:

Excluded:

• Live attenuated vaccines within 60 days prior to study entry. NOTE: Medically indicated killed or subunit vaccines (e.g., influenza, pneumococcal) do not exclude if administered at least 2 weeks from HIV immunizations.
• Experimental agents within 30 days prior to study entry.
• Prior HIV vaccines.
• Prior rabies immunization.

Prior Treatment:

Excluded:

• Blood products or immunoglobulin within 6 months prior to study entry. It is STRONGLY RECOMMENDED that any activity that might expose subject to HIV (unprotected sex or needle sharing) be avoided.