This document may be photocopied for professional use. HIV is a retrovirus. They are the major target of HIV and decline as HIV disease progresses. CD4 counts are a marker of the strength of the immune system. The percentage of CD4 cells and the absolute value of CD4 cells are good surrogate markers to tell us how much damage has occurred because of the HIV virus.
Antiretroviral treatment lowers the viral load which improves the prognosis.
The viral load measurement is an indicator of the prognosis of the individual. It is a useful surrogate marker to tell us what further damage is likely to occur to the immune system. The higher the number, the more likely further damage will occur to the CD4 cells at a faster rate.