Hiv-reservoirs
There was great hope that the virus had been defeated now that CD4 cells were protected by combination therapy, but this turned out not to be the case. Some CD4 cells infected with HIV go into ‘hibernation’.
These dormant cells cannot be recognised by the immune system, which means that antiretrovirals can’t target them either. The dormant cells are called the HIV reservoir.
A dormant CD4 cell like this can become active again (‘wake up’), allowing the virus from that cell to attack other cells. This is how the virus starts spreading again. People living with HIV must take antiretrovirals all the time to prevent reactivation of dormant dells.