The study aimed to evaluate the relationship between hepatitis B virus genotype and treatment response in children with chronic hepatitis B with specific treatment indications. This is a prospective cohort study, with a follow-up period of at least 12 months, conducted at Children's Hospital 1 and City Children's Hospital, Ho Chi Minh City, Vietnam. The patient's blood was taken to be tested for hepatitis B virus genotyping using Sanger sequencing at the Center for Molecular Biomedicine Ho Chi Minh City. The research hypothesis is that genotype is related to treatment response.

Inclusion Criteria:

• Children from 2 years old to under 16 years old are diagnosed with hepatitis B chronic disease AND
• HBsAg or HBV DNA: positive for at least six months AND
• Liver enzyme ALT: continuously increased by> 70 for male and > 50 for female (> 2 x ULN) AND
• The virus is proliferating: HBV DNA above 20,000 IU/mL (if HBeAg positive) OR HBV DNA above 2,000 IU/mL (if HBeAg negative) AND
• A parent or legal guardian of the pediatric patient obtains consent for them to participate in research.

Exclusion Criteria:

• HIV and hepatitis C co-infection
• Patients have other chronic liver disease (Wilson, autoimmune hepatitis)
• Patients are being treated with immunosuppressive drugs
• Psychomotor retardation, cerebral palsy, brain sequelae

Pediatric patients with chronic hepatitis B are indicated for drug treatment antiviral treatment at Children's Hospital 1 and City Children's Hospital, Ho Chi Minh City, Vietnam.