Although viral load testing is the standard for measuring the effectiveness of antiretroviral therapy, it is at best an indirect measure of changes in the immune system.
Several assays are now in development that measure cellular immune response.
These tests could lead to better ways of evaluating the clinical status of the immune system and provide greater insight into the mechanisms of immune reconstitution. There is a clear need to bring back the immune system. When those women take a break from their normal profession, they actually then get infected from the lack antigenic exposure. So the fact is that the low-level antigenic exposure of HIV, although not enough to infect them, allowed them to develop some sort of host protective immunity. When that went away, then they became infected and so it's raising a whole question of understanding the virus and the host immune system interaction.