The HIV set point is the viral load

Viral load

Viral load is a measure of the severity of a viral infection, and can be calculated by estimating the amount of virus in an involved body fluid. For example, it can be given in RNA copies per milliliter of blood plasma...

 of a person infected with HIV

HIV

Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...

, which stabilizes after a period of acute HIV infection. The set point is reached after the immune system

Immune system

An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...

 has developed HIV antibodies and begins to attempt to fight the virus. The higher the viral load of the set point, the faster the virus will progress to AIDS

AIDS

Acquired immune deficiency syndrome or acquired immunodeficiency syndrome is a disease of the human immune system caused by the human immunodeficiency virus...

; the lower the viral load of the set point, the longer the patient will remain in clinical latency. The only effective way to lower the set point is through highly active antiretroviral therapy.