The goal of this randomized clinical trial is to evaluate the safety and immunogenicity of the HIV Therapeutic DNA Vaccine (ICVAX) in participants with HIV-1 infection under antiretroviral therapy (ART). The study compares three delivery methods - Teresa -EPT I, PharmaJet Tropis, and PapiVax TriGrid EP - to induce antigen-specific T cell responses in the participants.

The primary objectives are to evaluate the safety of ICVAX delivered using three different devices in the participants within the period Day 0-Day 336, and to evaluate the antigen-specific T cell responses induced by ICVAX in the participants within the period Day 0-Day 168.

The participants will receive four injections of ICVAX administered at 4-week intervals. Following the final dose, participants will be monitored for 36 weeks.

Inclusion Criteria:

1. Tested positive for HIV-1 antibody;
2. Aged 18-60, both male and female;
3. BMI (body mass index) in between 18.5 and 24.9 kg/m2 (including upper and lower limits);
4. Received ART for ≥12 months; no drug resistance occurred during this treatment period;
5. Had <50 copies/ml of plasma HIV RNA for at least (≥) 12 months prior to screening visit;
6. Had ≥350 cells/μL of CD4+ T cells in the past 6 months and >200 cells/μL of CD4+ T cells before initiation of ART;
7. Adopted contraception method approved by the investigator from screening period until the end of study;
8. Understand the study and voluntarily sign the ICF.

Exclusion Criteria:

1. Women who are pregnant or breastfeeding or those who plan to give birth in coming two years (including the subject and his/her spouse);
2. ART has been suspended for more than 2 weeks continuously since ART initiation;
3. Participated in other clinical trials within 24 weeks before the screening visit;
4. Has any opportunistic infections or opportunistic tumors that require systemic treatment within 30 days before being recruited; Has any medical events that the investigator believes will affect the safety and immunogenicity evaluation of the drug;
5. Has a history of autoimmune diseases; Has hypersensitivity to the components of this drug including ICVAX recombinant plasmid, NaCl, Na2HPO4 and NaH2PO4·H2O, and shows severe allergies, such as dyspnea, edema and other symptoms after administration;
6. Received approved vaccines within the past 3 months;
7. Received any blood products, immunoglobulin products, or immunosuppressants within 12 weeks before being recruited;
8. Used interferon, systemic corticosteroids, or other immunosuppressants within the last 3 months (except local application);
9. Positive Hepatitis B surface antigen (HBsAg) within 12 months, or positive Hepatitis C virus antibody (HCV Ab) at screening with confirmatory HCV RNA positive;
10. Has any abnormal laboratory results including: neutrophil <1×109/L, serum creatinine > ULN, ALT or AST >1.5×ULN, hemoglobin < 11g/dL;
11. Has any medical history or clinical manifestations of any physical or mental illness that may affect the subject's completion of this study;
12. Sensitive to electrical pulse stimulation, such as those who are implanted with pacemaker/ Automatic Implantable Cardioverter Defibrillator (AICD), or those who have wearable medical electronic devices including electrocardiogram;
13. Needle phobia;
14. Have contraindications for intramuscular administration such as confirmed thrombocytopenia, any coagulation dysfunction or currently receiving anticoagulation therapy;
15. The investigator considers that he/she is not suitable to participate in this trial.

The results of this study will be publicly disseminated by ways of publication(s) in peer-reviewed scientific journal(s), presentation(s) in scientific conference(s), posting on public clinical trial registry(ies) and/or otherwise instead of individual participant data (IPD) sharing.