Patients currently enrolled in A5058s under A5057/A5058s Versions 1.0 and 2.0 will be given the option of continuing their participation in A5058s through this independent study. Rollover patients register to Step II and begin treatment/evaluations on A5058s at the same study week that they were on in Versions 1.0 and 2.0 of A5057/A5058s. New patients enter Step I and will not need to register to Step II. Step I patients are stratified on the basis of HIV viral load, antiretroviral history, and current antiretroviral treatment. Within each stratum, patients are randomized to 1 of the following 4 treatment arms: HIV-1 immunogen plus ALVAC placebo, HIV-1 immunogen placebo plus ALVAC placebo, HIV-1 immunogen placebo plus vCP1452, or HIV-1 immunogen plus vCP1452. Patients receive an injection at study entry and every 12 weeks thereafter until the end of the study, a minimum of 2 years. Step II patients receive the same treatment as patients in Step I. Patients are evaluated every 12 weeks for clinical, immunologic, and virologic parameters. Patients continue taking the antiretroviral treatment that they were taking at study entry until reaching a virologic relapse as defined in the protocol. If no response to a new drug regimen occurs, or the antiretroviral therapy is not changed, immunizations may continue as long as the viral load remains below 5,000 copies/ml.