The magnitude of the improvement of the mean CD4 cell count seen in this study is one of the largest reported for this regimen in literature . One of the reasons may be that patients initiated HAART at lower CD4 counts than in most other studies. There was a substantial improvement in the CD4 counts initially (after 3-6 months) which was subsequently sustained. The initial improvement is postulated to be due to redistribution of memory CD4 cells from the lymph nodes into the blood and later improvement because of the production of naïve CD4 cells. Although a significant proportion of patients started therapy at advanced stages of HIV infection there was still a remarkable improvement in CD4 counts indicating the potency of this regimen and these formulations.