This study was a multicenter, prospective randomized controlled clinical study. A total of 60 HBV-infected infants with ALT ≤5 times the upper limit of normal (ULN) and without pathological jaundice were enrolled and randomized 1:1 into two groups: the control group and the antiviral treatment group. HBV-infected infants in the treatment group were treated with LAM before the age of 1 year and then combined with regular interferon for 52 weeks if they were still positive for HBV DNA and/or HBsAg after reaching the age of 1 year. The control group was followed up synchronously. Follow-up was conducted every 3 months during the study period. The main efficacy evaluation indexes: HBsAg conversion (functional cure) rate, HBeAg conversion rate, HBeAg seroconversion rate, HBV DNA conversion rate, HBsAg seroconversion rate, and ALT reversion rate at the end of 12 months of treatment and at 2 years of age.

Inclusion Criteria:

• a. Age ≤ 1 year;
• b. HBsAg and HBV DNA positive;
• c. ALT ≤ 5 times the upper limit of normal (ULN) and no pathologic jaundice (two consecutive tests with an interval of 2 weeks - 3 months).
• d. Parents are willing to participate in the study and sign an informed consent form, for children without parents, all legal guardians of need to give informed consent.

Exclusion Criteria:

• a. Combined viral infections such as HAV, HCV, HDV, HEV, HIV, EBV, CMV, etc;
• b. Combination of other liver diseases, such as autoimmune hepatitis, drug-induced liver injury, Wilson's disease;
• c. WBC <9 × 10^9/L, or PLT <90 × 10^9/L;
• d. Combination of other systemic serious diseases or hereditary diseases, etc;
• e. Other conditions deemed by the investigator to be unsuitable for participation in this study.