Long-term nonprogressors (LTNPs), are individuals infected with HIV, who maintain a CD4 count greater than 500 without antiretroviral therapy with a detectable viral load. Many of these patients have been HIV positive for 30 years without progressing to the point of needing to take medication in order not to develop AIDS. They have been the subject of a great deal of research, since an understanding of their ability to control HIV infection may lead to the development of immune therapies or a therapeutic vaccine. The classification "Long-term non-progressor" is not permanent, because some patients in this category have gone on to develop AIDS. Long-term nonprogressors typically have viral loads under 10,000 copies /mL blood, do not take antiretrovirals, and have CD4+ counts within the normal range. Most people with HIV not on medication have viral loads which are much higher. It is estimated that around 1 in 500 people with HIV are long-term nonprogressors. Without the symptoms of AIDS, many LTNP patients may not know they are infected. Genetic traits that confer greater resistance or more robust immune response to HIV are thought to explain why LTNP patients are able to live much longer with HIV than patients who are not LTNP. Some LTNP are infected with a weakened or inactive form of HIV, but it is now known that many LTNP patients carry a fully virulent form of the virus. Genetic traits that may affect progression include: The 'long-term nonprogressors' term is used for HIV carriers only but the wide term asymptomatic carrier is well known for many other infections.

Clearance of the virus

Recently, there have been reports of elite controllers who maintain undetectable viral loads. In 2019, an American named Loreen Willenberg was announced as the first such case. In 2021, an Argentinian dubbed "the Esperanza patient" after the town in which she lives was also identified. Willemberg had received antiretroviral therapy but stopped treatment at some point. The Argentinian patient took antiretroviral therapy only while pregnant, but her viral load was nevertheless reported to be undetectable years after treatment discontinuation. This could inform the development of a "sterilising cure."