Inclusion Criteria:
1. Confirmed HPV16 and/or HPV18 infection of the cervix, vulva, vagina or anus lasting for more than 1 year at screening; patients who decline surgical treatment or have failed prior pharmaceutical therapy (e.g., 5% imiquimod cream, 1% cidofovir gel);
2. Histopathological diagnosis of ≤ Grade 2 CIN, VIN, VAIN or AIN via colposcopy or anoscopy at a local hospital (lesion specimens obtained within 3 weeks prior to the first study treatment); willing to provide biological samples throughout the study;
4.Screening electrocardiogram shows normal findings or no clinically significant abnormalities as judged by the investigator; 5.Fertile eligible participants must agree to use reliable contraceptive methods together with their partners during the trial and for at least 1 year after the last administration (hormonal contraceptives, barrier methods, or abstinence); female participants of childbearing potential must have a negative serum pregnancy test within 7 days before enrollment;
Exclusion Criteria:
1. Cytology results obtained during screening showing any of the following: adenocarcinoma in situ (AIS), atypical glandular cells favor neoplasia (AGC-FN), invasive carcinoma, etc.
2. Received disease-related treatments within 4 weeks prior to the first vaccination, including pharmaceutical therapy (e.g., immunomodulators, fluorouracil ointment, recombinant human interleukin-2 injection), physical therapy (cryotherapy, laser therapy, photodynamic therapy), or surgical treatment.
3. Prior administration of any therapeutic HPV vaccine (licensed prophylactic HPV vaccines are permitted).
4. Received any vaccine within 4 weeks or 2 weeks prior to the first vaccination.
5. Past or current diagnosis of other malignant tumors (exceptions: completely treated and cured ductal carcinoma in situ of breast, basal cell carcinoma of the skin, superficial bladder tumors, or any malignancy cured for more than 5 years with no evidence of recurrence prior to study entry).
6. Active autoimmune disease or medical history of autoimmune disorders.
7. Other immunocompromised conditions, including subjects receiving immunostimulants or immunosuppressants within 3 months (oral or intravenous administration lasting more than 14 consecutive days); subjects receiving whole blood, plasma or immunoglobulin therapy within 1 month; subjects with clinically diagnosed impaired or deficient immune function; or functional asplenia or splenectomy due to any cause.
8. Severe allergic history, history of allergic disorders, or allergic diathesis.
9. Participation in another clinical trial within 4 weeks prior to the first study vaccine administration.
10. Underwent major surgery or sustained significant trauma within 4 weeks prior to the first study vaccine administration.
11. Active hepatitis B (HBV viral load \>1000 copies/mL or 200 IU/mL; prophylactic antiviral therapy other than interferon is allowed); hepatitis C virus infection.
12. History of immunodeficiency or positive HIV antibody test result.
13. Systemic active bacterial, fungal or viral infection (defined as infection requiring intravenous antibacterial, antifungal or antiviral agents).
14. Long-term (≥7 consecutive days) systemic glucocorticoid therapy (prednisone ≥20 mg/day or equivalent dose) or other immunosuppressants (short-term glucocorticoids for prophylaxis and topical glucocorticoids including ophthalmic, intra-articular, intranasal and inhaled formulations are permitted). Current or planned use of anti-rheumatic or immunomodulatory agents such as azathioprine, cyclophosphamide, cyclosporine, methotrexate and TNF-α inhibitors (infliximab, adalimumab, etanercept, etc.).
15. History of solid organ transplantation or bone marrow transplantation.
16. Pregnant or breastfeeding female subjects.
17. Any other conditions that may interfere with study procedures, compromise the subject's maximum benefit from participation, or confound study outcomes, including history of psychiatric disorders, drug addiction or substance abuse, or any other clinically significant unstable medical conditions (e.g., chronic renal failure).
