Arm A: one injection of vCP1452 at W0, W4, W8 and W20 + HAART, for a total of 4 injections Arm B: one injection of vCP1452 at W4, W8 and W20 + HAART, for a total of 3 injections Arm C: one injection of placebo at W0, W4, W8 and W20 + HAART, for a total of 4 injections or at W4, W8 and W20 + HAART, for a total of 3 injections