In the main study, patients with HIV-1 infection of less than 120 days are given the option of taking a potent ART combination of abacavir (ABC), efavirenz (EFV), indinavir (IDV), and lamivudine (3TC) for 96 weeks. [AS PER AMENDMENT 9/15/00: Patients choose either Regimen 1: ABC, 3TC, IDV, and ritonavir (RTV) or Regimen 2: ABC, 3TC, and EFV.] Patients who decline treatment provide a concurrent, non-randomized comparison group. These patients may choose to be considered for study treatment at any time or to start antiretrovirals provided through another source. [AS PER AMENDMENT 9/15/00: If a patient who initially does not start therapy subsequently starts antiretroviral therapy provided by the study (within the 120-day limit), the visit schedule is re-set.] During the treatment period, all patients undergo regular physical exams and blood tests to characterize T cells, viral resistance, antibody responses, and other markers. Patients presenting within 30 days of HIV-1 infection undergo leukapheresis (where available) prior to starting ART. At Month 12, these patients and all untreated patients undergo leukapheresis to assess the proportion of latently infected CD4+ T cells. In addition, all patients in the main study and patients in 2 comparison groups (Cohorts A and B) participate in 1 of 2 substudies of antibody responses to neoantigen. Volunteers are recruited to 2 cohorts to serve as controls. Cohort A volunteers have established HIV-1 infection. Cohort B volunteers are HIV-1 seronegative but at high risk for HIV. In the first substudy, hepatitis B-seronegative patients from the main study and from Cohorts A and B receive hepatitis B vaccine at Weeks 40, 44, and 64 and undergo humoral and cellular response assessments at Week 68. In the second substudy, patients from the main study and from Cohorts A and B who did not qualify for the hepatitis B vaccination undergo intramuscular vaccination with tetanus toxoid at Week 64 and immune responses are assessed at Week 68. Volunteers in Cohorts A and B receive no anti-HIV medication as part of these substudies.