The purpose of this study is to compare two drugs (nelfinavir [NFV] and efavirenz [EFV]) used in start-up anti-HIV treatment. Doctors want to see if one is better than the other in extending the time that viral load (level of HIV in the blood) is kept low. The study will also look at the response of the immune system to each drug.

Patients are randomized to initiate therapy and receive either nelfinavir (NFV) or efavirenz (EFV) in the first regimen (R1). All patients also receive zidovudine (AZT) and lamivudine (3TC). Patients are further randomized in a factorial fashion and by stratification based on HIV RNA level (less than 10,000, 10,000-100,000, or greater than 100,000 copies/ml) to be administered a single injection of a neo-antigen (KLH) at Week 12, 24, or 48. Therapy continues until switch criteria are met either before or after Week 24. When switch criteria are met, patients advance to the next regimen (R2).

R2 patients previously taking NFV switch to EFV; those randomized to EFV switch to NFV; the additional NRTIs change to stavudine (d4T) and didanosine (ddI). Therapy is continued for an additional 24 weeks.

Inclusion Criteria

Patients may be eligible for this trial if they:

• Are HIV-positive.
• Have a CD4 count of at least 100 cells/mm3.
• Have a viral load of at least 5,000 copies/ml.

Exclusion Criteria

Patients may not be eligible for this study if they:

• Have taken any antiretroviral (anti-HIV) agent.