A

Infants born to an HBsAg-positive mother—whether she is HBeAg positive or negative—should receive hepatitis B immune globulin and the first dose of hepatitis B vaccine within 12 hours of birth to provide immediate passive protection and induce long-term active immunity, sharply reducing perinatal transmission risk [Schillie 2015, PMID 26447601; AAP Policy 2017, PMID 28847980].