A Comparative Phase I Clinical Study of HIVAC-1e and Smallpox (Vaccinia) Vaccines in Previously (Vaccinia) Vaccinated and Unvaccinated Volunteers

Inclusion Criteria Concurrent Medication: Allowed: * All drugs, medications, and therapy which, by virtue of direct pharmacologic action or possible drug interaction, could influence the intended effects of the study vaccine or mask its side effects may be concomitantly administered only by prescription by the Principal Investigator and must be documented on the case report form (CRF). * Any drug, even aspirin, which is administered after vaccination and during the follow up periods must be documented on the patient's CRF. Exclusion Criteria Co-existing Condition: Patients with the following conditions or symptoms are excluded: * Failure to meet any criteria listed under Inclusion Criteria. * Development of active eczema or other skin condition which would increase the risk of secondary vaccinia lesions. * Appearance of serologic or clinical evidence of HIV infection prior to vaccination. * Current evidence of clinically active viral infections such as Mononucleosis, Epstein-Barr Virus, or cytomegalovirus which may affect immunocompetence. * Active and overt parasitic, mycobacterial, or pyogenic infections that affect tests designated in Inclusion Criteria. Concurrent Medication: Excluded: * All drugs, medications and therapy not prescribed by the Principal Investigator, and not documented on the case report form (CRF). * Any drug, even aspirin, which is administered after vaccination and during the follow up periods which is not documented on the patient's CRF. Patients with the following are excluded: * Failure to meet any criteria listed under Inclusion Criteria. * Appearance of serologic or clinical evidence of HIV infection prior to vaccination. * Current evidence of clinically active viral infections. * Active and overt parasitic, mycobacterial, or pyogenic infections that affect tests designated in Inclusion Criteria. Risk Behavior: Patients who do not agree to behave sexually in a manner that will minimize the risk of HIV infection for the duration of the study are excluded. Patients must: * Be HIV seronegative. * Have excellent general health. * Be unable to bear children. * Have no immediate household contacts, sex partners, intimate contacts. * Be free of clinical skin diseases. * Have signed an informed consent. * Control subjects receiving Smallpox vaccine will also be selected under the same inclusion criteria. They may be recruited from low risk behavior populations; from laboratory and hospital employees providing service to the study who would normally require Smallpox vaccination; and may be heterosexual, homosexual, or bisexual. Patients must agree to behave sexually in a manner that will minimize the risk of HIV infection for the duration of the study.