The QD regimen will be made up by didanosine (capsule-CT) + lamivudine + efavirenz, a regimen containing three tablets that must be taken together at night and which is the QD regimen with most experience to date. We have chosen as combination of NRTI didanosine and lamivudine, drugs authorized for QD use with a very good safety profile and no interactions with each other and with efavirenz. The combination of didanosine and lamivudine is highly attractive and is in fact recommended for the starting HAART by various agencies though not at the same level as the combination of zidovudine and lamivudine (which can be only administered BID) just because there are less randomized clinical trials with the former than with the latter combination of NRTI. Therefore, one of the strengths of the study is that it proposes the possibility of assessing the combination of didanosine and lamivudine in a starting HAART regimen.