Current CDC statement of transmission routes; CDC estimates ~640,000 adults in the U.S. have chronic hepatitis B and about 1 in 2 infected people do not know it. Directly relevant to flag F1: infants can acquire HBV perinatally and by household contact — not only via transfusion or drug use. (Page predates the Dec 16, 2025 schedule change and still lists 'All infants' under CDC vaccination recommendations.)
HBV is transmitted when blood, semen, or another body fluid from a person infected with the virus enters the body of someone who is uninfected.
Current CDC statement of transmission routes; CDC estimates ~640,000 adults in the U.S. have chronic hepatitis B and about 1 in 2 infected people do not know it. Directly relevant to flag F1: infants can acquire HBV perinatally and by household contact — not only via transfusion or drug use. (Page predates the Dec 16, 2025 schedule change and still lists 'All infants' under CDC vaccination recommendations.)