Although an HIV infection can induce weak immune responses, current HIV immunotherapy using consensus antigens has not shown consistent clinical activity. The absence of clinical activity is associated with an inability to raise cytotoxic T lymphocytes (CTL) against HIV antigens and a failure to induce T cell memory. While strong immune responses may be generated to a consensus antigen, those responses do not offer antiviral protection against a patient's individual viral burden. The infecting virus' antigen variability likely prevents the establishment of effective CD4+ T cell memory and a strong CD8+ T cell effector arm.