This is a multicenter, open-label, non-randomized, Phase 1 clinical study with single-dose and multiple-dose dose-escalation cohorts. The study is designed to evaluate the safety, tolerability, and pharmacokinetic characteristics of TVAX-028 in patients with chronic hepatitis B virus infection

Inclusion Criteria:

• 1. Subjects voluntarily sign the informed consent, fully understand the study content, and are willing and able to comply with all trial procedures.
• 2. Male or female, aged 18 to 65 years.
• 3. Has a clinical diagnosis of chronic hepatitis B virus infection based on protocol-defined criteria.
• 4. Is receiving stable antiviral treatment with a single nucleos(t)ide analogue before enrollment. Has adequately suppressed HBV DNA and acceptable liver function based on protocol-defined criteria before the first administration of adjuvant or TVAX-028.
• 5. Has HBeAg-negative chronic hepatitis B virus infection based on protocol-defined criteria.
• 6. Has hepatitis B surface antigen (HBsAg) levels within the protocol-defined range before the first administration of adjuvant or TVAX-028.
• 7. Has no evidence of autoimmune liver disease based on protocol-defined testing and investigator assessment.
• 8. Participants of childbearing potential must agree to use effective contraception for the protocol-defined period.

Exclusion Criteria:

• 1. Has liver disease other than chronic hepatitis B virus infection that may interfere with study participation or interpretation of study results
• 2. Has evidence or suspected evidence of hepatocellular carcinoma, cirrhosis, clinically significant hepatic space-occupying lesions, or clinically significant liver fibrosis based on imaging, laboratory testing, or non-invasive liver assessment.
• 3. Has clinically significant abnormalities in laboratory tests, including but not limited to liver function, renal function, hematology, coagulation, or electrolyte parameters, based on protocol-defined criteria.
• 4. Has received interferon or pegylated interferon treatment within the protocol-defined period before the first administration of adjuvant or TVAX-028, or plans to receive such treatment during the study.
• 5. Has received immunosuppressive therapy within the protocol-defined period before the first administration of adjuvant or TVAX-028.
• 6. Has received corticosteroid therapy within the protocol-defined period before the first administration of adjuvant or TVAX-028, except for permitted topical or inhaled corticosteroids.
• 7. Has clinically significant cardiovascular, renal, pancreatic, or other systemic disease that may increase study risk or interfere with study assessments.
• 8. Has inadequately controlled diabetes mellitus or hypertension based on protocol-defined criteria.
• 9. Has evidence of clinically significant co-infection, including hepatitis C virus, hepatitis D virus, human immunodeficiency virus, or active syphilis infection.
• 10. Has a history of malignancy within the protocol-defined period before the first administration of adjuvant or TVAX-028, except for conditions permitted by the protocol.
• 11. Has previously received organ transplantation.
• 12. Has a history of severe drug and food allergy, or is known to be allergic to any component of the investigational product or related products.
• 13. Has a history of drug abuse or clinically significant alcohol abuse within the protocol-defined period before the first dose.
• 14. Has a history or current diagnosis of psychiatric disease, severe depression, or other condition that may affect compliance with study procedures.
• 15. Has a history of severe allergy, or is known or suspected to be allergic to any component of the investigational product, adjuvant, or related products.
• 16. Has participated in another clinical trial of an investigational drug, biologic, medical device, or vaccine within the protocol-defined period before the first administration of adjuvant or TVAX-028.
• 17. Is pregnant or breastfeeding.
• 18. Is considered by the investigator to be unsuitable for participation in this study for any other reason.