The goal in either group is to improve the natural immune response against HIV, hopefully making it possible to control viral replication with less aggressive treatment. Over time, though, this response often fades. In both cases, the decline is thought to be associated with the success of anti-HIV therapies, which dramatically reduces the amount of new virus being produced. Because of this lowered viral activity, the immune system sees less and less of the virus and thus does less to mount a defense against it. This might restore a person's sensitivity to drugs that had previously become ineffective due to resistance and allow the drugs to work again, at least temporarily.
Some people develop bothersome side effects to anti-HIV drugs, either quickly or after years of use.
Side effects such as liver and kidney problems can become serious, even life-threatening, and limit a person's ability to use the drugs. Other effects, such as lipodystrophy , may have unknown long-term consequences in addition to their visible impact. Many also develop psychological obstacles. Over time, it gets more difficult to adhere to the regimen. At the start of their STIs, the seven participants had low level CTL responses and undetectable viral loads.