The goal of this clinical trial is to evaluate the safety, tolerability, immunogenicity and Pharmacokinetics (PK) characteristics of AHB-171 Injection in healthy participants (Part A) and participants with chronic hepatitis B (CHB, Part B), and assess its preliminary efficacy in CHB participants.

Inclusion Criteria:

• Healthy Participants:
• Male or female participants, aged 18-55 years old (inclusive);
• Body mass index between 18.0 and 28.0 kg/m^2 (inclusive);
• Laboratory safety tests during the screening period, 12-lead electrocardiogram (ECG), abdominal ultrasound, thyroid ultrasound, chest anteroposterior position, etc., are assessed by the investigatoras normal or abnormal without clinical significance;
• Female participants of childbearing potential must not be pregnant or lactating, must have a negative pregnancy test at screening, and must agree to use effective contraceptive methods and refrain from donating eggs from screening until 6 months after the last dose of the study drug.
• Male participants must agree to use highly effective contraceptive methods (to ensure effective contraception for their female partners of childbearing potential) and refrain from donating sperm from screening until 6 months after the last dose of the study drug. Liver and kidney function tests meet the requirements at the time of screening.
• CHB Participants:
• Male or female participants, aged 18-65 years old (inclusive);
• Body mass index between 18.0 and 32.0 kg/m^2 (inclusive);
• Participants who take effective contraceptive measures as required;
• HBsAg > 100 IU/mL and ≤ 3000 IU/mL, and HBV DNA < 100 IU/mL at screening.
• Have received stable treatment with NA for at least 6 months and stable on the same NA for at least 3 months before screening.

Exclusion Criteria:

• Healthy Participants:
• Currently participating in another study, or within 5 half-lives/3 months of the last dose of a previous investigational product.
• Presence diseases (cardiovascular, neurological, renal, immunological, metabolic, etc.) or malignant tumors.- Major surgery or severe trauma within the past 6 months.
• Acute infection (e.g., influenza, gastroenteritis) within 14 days; vaccination within 28 days prior to screening.
• Allergy to any investigational drug component.
• Heavy Smoking (> 5 cigarettes/day); history of drug/alcohol abuse; consumption of caffeine or alcohol within 48 hours before dosing.
• Blood donation/loss ≥400 mL or transfusion within 12 weeks, or plan to donate during study.
• Abdominal skin issues that may affect drug injection/observation.
• Positive for HBV, HCV, HIV, or syphilis.
• Clinically significant ECG abnormality or TdP risk factors.
• Any condition judged unsuitable by investigator.
• CHB Participants:
• Currently participating in another study, or within 5 half-lives/3 months of the last dose of a previous investigational product.
• Presence of ascites, gastrointestinal bleeding, hepatic encephalopathy, or varices.
• History or suspicion of hepatocellular carcinoma (HCC); AFP > 50 ng/mL.
• Diagnosed or Suspected cirrhosis within 12 months.
• History of transplantation, autoimmune diseases, or severe systemic diseases (besides chronic HBV).
• Use of ASO, siRNA (oligonucleotide therapies), or interferon within 12 months.
• Major injury/surgery within 6 months, planned surgery during study, or acute infection within 14 days.
• Allergy to any investigational drug component.
• Blood donation/loss ≥400 mL or transfusion within 12 weeks, or plan to donate during study.
• Abdominal skin issues that may affect drug injection/observation.
• Key laboratory result not suitable for clinical trial.
• HIV, HCV, or active syphilis infection; uncured hepatitis A, D, or E.
• Clinically significant ECG abnormality or TdP risk factors.
• Any condition judged unsuitable by investigator.