Early initiation of antiviral treatment for two infants with acute HBV infection: Beneficial or unfavorable?

Mother-to-child transmission is the major route of hepatitis B virus (HBV) infection in children, and antiviral therapy is generally deferred in infancy due to presumed immune tolerance. Here, we report the clinical course and treatment response of two infants younger than 6 months with HBV infection who initiated antiviral therapy due to elevated serum transaminase levels indicative of an immune-active status. Notably, Case #01 achieved a functional cure after 25 months of antiviral treatment. Case #02 did not achieve a functional cure but attained HBV DNA clearance and HBeAg seroconversion at 12 and 5 months of therapy, respectively. At the last follow-up visit (month 67), the HBsAg level of Case #02 was 10.70 IU/mL. These findings suggest that early antiviral intervention, initiated before 6 months of age, may be beneficial for infants with HBV infection who are in an immune-active status. A potential treatment window may exist even during early infancy; however, treatment strategies should be individualized and guided by careful clinical assessment.