after HIV enters the human body, it initially enters macrophages and subsequently targets helper T-lymphocytes (TH) The virus replicates within these T-cells to produce progeny viruses, which are then released into the blood to attack other helper T-lymphocytes This cycle repeats, leading to a progressive decrease in the number of helper T-lymphocytes in the infected person's body This depletion of helper T-cells is what ultimately makes the patient immuno-deficient and vulnerable to opportunistic infections