Model predicts up to 83% more chronic HBV infections in the US — Live Science
Modeling of possible changes to hepatitis B vaccination recommendations in the United States has shown that the number of chronic infections among young people could increase significantly. Researchers assessed the consequences of abandoning universal vaccination of newborns in the first hours after birth, Live Science reports.
Previously, the US Centers for Disease Control and Prevention recommended administering the first dose of the hepatitis B virus vaccine to all newborns shortly after birth. In December 2025, the Advisory Committee on Immunization Practices advised ending the universal recommendation, and the CDC accepted this advice. However, implementation of the new approach is currently suspended due to legal action.
Consequences of delaying vaccination
The proposed approach provides for administering a dose immediately after birth only to children whose mothers have a positive or unknown HBV status. Mothers with a negative test result are advised to discuss with a doctor whether their child needs a birth dose. If the vaccination is not given immediately, the vaccination series should begin no earlier than at two months of age.
According to the authors' calculations, among children born in 2026, delaying the first dose until two months of age could increase the number of chronic HBV infections by age 20 by 19% compared with universal vaccination at birth.
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Shared decision-making scenario
The scientists also modeled a scenario in which parents and a doctor decide together when, or whether, to begin the vaccination series at all. The authors assumed that under the delayed strategy, about 87% of children would complete the full vaccination course by age two, compared with 50% under the shared clinical decision-making approach.
At this level of coverage, the number of chronic infections acquired by age 20 could increase by 83%. According to the model's estimate, approximately 1.8 million people in each annual age cohort could remain susceptible to HBV at age 20, whereas under universal vaccination at birth there would be fewer than 250,000.
The hepatitis B virus can be transmitted from mother to child during childbirth or after birth through contact with even small amounts of bodily fluids, including blood. More than 90% of infections acquired in infancy or early childhood become chronic. In all 1,000 modeling variants, vaccination at birth resulted in fewer chronic cases than either of the two alternative scenarios.
