Subjects are asked to discontinue PCP prophylaxis if antiretroviral therapy has resulted in a sustained CD4 increase greater than 200 cells/mm3 on two measurements at least 12 weeks apart. They will be evaluated for symptoms and CD4 counts every 8 weeks as well as plasma for HIV-RNA every 16 weeks for 18 months. Subjects whose CD4 count falls to less than 150 cells/mm3 or between 150 and 200 cells/mm3 will have the CD4 count re-evaluated immediately or within 4 weeks. If the second CD4 count is less than 200 cells/mm3 for either case, conventional PCP prophylaxis will be resumed and the subject will be followed on study. Subjects will be followed during study by physical exams and laboratory tests at Weeks 4, 8, and every 8 weeks thereafter.