To determine the physiological and immunological responses in healthy HIV seronegative adult volunteers vaccinated with a) the HIVAC-1e (vaccinia-HIV) vaccine expressing the envelope glycoproteins of HIV and b) the Wyeth smallpox vaccine. The parameters to be studied will include: 1. The course of physiological responses to vaccination, including (a) lesion development, progression, and resolution; (b) physiological changes such as temperature, malaise, itching at the site, etc. and (c) any observable AE. 2. The appearance, identity, quantity, and duration of humoral antibodies against HIV and vaccinia virus. 3. The appearance, identity, quantity, and duration of cell-mediated immunity against HIV and vaccinia virus. 4. The adequacy of a procedure using a special dressing to contain viral shedding from the vaccination site. 5. The safety, humoral and cellular immune responses of a booster injection of the recombinant subunit gp160 vaccine (MicroGeneSys) in HIVAC-1e recipients.