3. Maintain failing therapy. This strategy has the potential advantage of decreasing the rate of CD4 cell loss. It is known that certain mutations of HIV decrease viral fitness and produce a less pathogenic virus. Consequently, compared to wild-type virus, CD4 destruction is decreased in the presence of resistance mutations. The very important risk inherent to this strategy is the accumulation of new antiretroviral mutations if the regimen is maintained. Due to cross-resistance among antiretroviral drugs, accumulation of new mutations decreases the chances of success of a new salvage regimen.