Modeling the synergy of maternal screening and newborn HBV vaccination

Hepatitis B virus (HBV) infection acquired at birth or during early infancy can lead to lifelong health complications, including chronic liver disease. Despite longstanding recommendations for prenatal screening, an estimated 12% to 16% of pregnant individuals in the US are not screened for hepatitis B. This gap leaves a portion of newborns at risk for undetected exposure.

Vaccination at birth serves as a safeguard, particularly for infants born to mothers whose hepatitis B status is unknown. 

Researchers at Boston Medical Center (BMC) and Boston University (BU) School of Public Health used simulation modeling to examine how different levels of newborn vaccination coverage and maternal screening influence HBV infection rates in infants across the US. The findings, published in JAMA Pediatrics, compared outcomes under varying real-world conditions to better understand how screening and vaccination work together to prevent transmission. 

The study found that lower vaccination coverage among infants born to unscreened mothers was associated with a substantial increase in HBV infections. When vaccination coverage in this group was estimated at 10%, based on historical coverage during a brief pause in the birth dose vaccination recommendation in 1999, the model projected more than 1,000 additional infections.

When coverage increased to 80%, consistent with current levels under universal birth dose vaccination, the projected increase dropped to just over 100 additional infections, representing a tenfold reduction. 

Our modeling shows how sensitive hepatitis B prevention is to changes in vaccination coverage at birth. Even under optimistic assumptions, lower coverage among higher-risk groups leads to increased infections, reinforcing the importance of maintaining high uptake to protect infants."

Margaret Lind, PhD, Assistant Professor, Epidemiology, School of Public Health, Boston University

Researchers also found that very high levels of maternal screening would be required to offset the increase in infections associated with lower vaccination coverage. The model estimated that screening rates would need to reach approximately 98% to maintain similar levels of protection, a level that has not been achieved nationally in practice. 

"Even small drops in birth dose vaccination can increase HBV infection risk, especially for infants of unscreened mothers," says Rachel Epstein, MD, MSCE, pediatric and adult infectious disease clinician-scientist at BMC and assistant professor of medicine at BU Chobanian & Avedisian School of Medicine. "This study highlights the importance of consistent prevention strategies to protect newborns and reduce hepatitis B nationwide."