Open-label, Phase I/IIa Study of VAC-3S in HIV-1 Patients Who Showed an Immune Response to VAC-3S During IVVAC-3S/P1

Inclusion Criteria: * HIV-1 infected patient, * Age between 18 and 60 years, * ART (Anti Retroviral Therapy) initiation ≥ 1 year ago, * Plasma HIV RNA ≤ 200 copies/ml in the past 12 months, * Plasma HIV RNA ≤ 50 copies/ml at the screening visit, * CD4+ T cell count ≥ 200 cells/mm3, * Nadir CD4+ T cell count ≥ 100 cells/mm3, * Contraception in women with child-bearing potential, * A total anti-3S titer ≥ 20 A.U. at any time point of IVVAC-3S/P1 clinical trial, * Per protocol subject having completed the IVVAC-3S/P1 study. * Patient affiliated to a social security system, * Patient who has understood the protocol design and provided a signed written informed consent form, * Patient who is willing and capable of cooperating to the extent and degree required by the protocol, * Patient whom the investigator believes he/she can and will comply with the requirements of the protocol (e.g. completion of the diary cards, return for follow-up visits) and he/she will be available for all scheduled visits at the investigational site. Exclusion Criteria: * Administration of VAC-3S in the past year, * Chronic active liver disease, * History of HCV co-infection or ongoing replicating HCV (positive RT-PCR) or HBV (positive HbS Ag) coinfection, * Any immunotherapy (e.g. IL-2, IL-7, growth hormone…) in the past year at the exception of VAC-3S, * Any immunosuppressive therapy (glucocorticoids, cyclosporine, methotrexate) or chronic non-steroidal anti-inflammatory treatment in the past month, * Ongoing pregnancy, * Breastfeeding women, * Patient with known sensitivities to investigational drug (see please the CIB), * History of allergy to any vaccine, * Any severe chronic condition that would interfere with the study, * History of auto-immune disease, * Organ transplant, * Splenectomy, * Psychiatric disorder significant enough to hinder participation as assessed by the investigator, * Patient who has participated in a clinical research trial in the 30 days preceding the screening visit (V-1M-1). * Patients with contraindications to intramuscular injections including, but not limited to, patients with thrombocytopenia and/or anomalies of the coagulation system, * Any uncontrolled chronic or acute condition that in the opinion of the investigator would compromise the safety of the patient or the ability to properly administer the study.