<qa>  How many HIV-positive subjects had failed at least two HAART regimens?In the present trial, T cells will be harvested from infected individuals, transduced ex vivo with the vector at the University of Pennsylvania, and then reintroduced by autologous transfusions. VIRxSYS recently completed a Phase 1 clinical study at the University of Pennsylvania of the vector VRX496 in 5 HIV-positive subjects who had failed at least two HAART regimens. Data available to date for the primary endpoints, viral load and CD4 counts, are promising. Specifically, 4 of 5 subjects had stable or increased CD4 counts, and viral loads were stable in 4 of 5 patients, and decreased by 1.7 log in 1 of 5 subjects following a single infusion of VRX496 T cells. In the present trial, subjects will receive up to 6 infusions of VRX496 modified CD4 T cells, and then undergo a series of tests, including rectal mucosal biopsies, to determine the longevity and trafficking of the VRX496 T cells. In addition, subjects will have the opportunity to have a supervised drug holiday structured treatment interruption to determine if the VRX496 have an antiviral effect. 