For many years it was unclear how to stop HIV from reproducing because it made so many different copies of itself. When a drug was used to stop it, eventually one of those different copies would, by chance, be able to get around the drug. But when several kinds of antiviral drugs were used in combination, they created such a powerful blockade that the virus was unable to reproduce quickly, and so resistance could be avoided or postponed. Many people who can tolerate the new medicines have levels of virus so low that even the most sensitive of tests cannot measure them. As long as the medicines are taken on schedule, t-cells come back, and some healing of the damage caused by the virus takes place.
Side effects cause some people to stop taking the medicines.
Some combinations may not be completely effective at reducing super high levels of virus down to the very low amounts needed to avoid resistance. It is therefore reasonable to be concerned how long even at very low levels of virus, the drugs can keep the virus at bay. Finally, there is fear that some long term side effects, such as high levels of cholesterol, or fat redistribution, or diabetes created by drugs, may slowly get worse and limit the length of time people can use some drug combinations, even if the treatments stop HIV effectively. For these reasons, as well as the cost of continuous medication and the psychological burden of constant compliance with drug scheduling, it is important to see if there is a better way to manage the illness. It is a mistake to assume that the new antiviral drugs are the only thing that stops HIV from reproducing and causing damage.