HBV Birth-Dose Alternatives Linked to More Infections in Model
Key Takeaways
- In a modeled US infant birth cohort, shared decision-making about hepatitis B vaccination projected 83% more childhood chronic HBV infections than universal birth-dose vaccination.
- Deferring vaccination until age 2 months projected 19% more childhood chronic HBV infections than the universal birth-dose approach.
- Both alternatives left more people susceptible to HBV at year 20 than universal birth-dose vaccination in the model.
Investigators used a Markov cohort state transition model of perinatal and childhood HBV infection in Mohareb and colleagues' Annals of Internal Medicine modeling study. They modeled a one-year 2026 cohort of 3.6 million US-born infants over 20 years, comparing universal hepatitis B vaccination at birth, vaccination beginning at 2 months, and vaccination through shared decision-making. Assumed childhood vaccine completion was 91.1%, 87.1%, and 50%, respectively. These percentages were model inputs, not observed effects of policy changes. Published inputs also covered maternal HBV prevalence, hepatitis B surface antigen testing sensitivity, and age-stratified chronic infection risk. The investigators projected chronic infections and HBV susceptibility as separate outcomes.
Projected childhood chronic HBV infections in the modeled cohort numbered 255 with universal birth-dose vaccination (95% uncertainty interval [UI], 130 to 530), compared with 303 when vaccination began at 2 months (95% UI, 155 to 610). Shared decision-making yielded 467 projected chronic infections (95% UI, 209 to 1032).
At year 20, the modeled birth cohort included 232,000 people susceptible to HBV under universal birth-dose vaccination, 474,000 under deferral, and 1,806,000 under shared decision-making. Susceptibility captures those still vulnerable to HBV rather than those with chronic infection.
Under a higher-risk scenario incorporating lower vaccine coverage, greater maternal HBV prevalence, and greater horizontal infection risk, the model projected 1,700 childhood chronic infections with deferral and 2,192 with shared decision-making. These are scenario-specific projections, not an observed rise in infections.
The authors identified uncertainty about horizontal HBV infection risk as a limitation. Their comparisons describe hypothetical alternatives if fully implemented, with vaccination coverage and infection risk specified as inputs. The projected infections and later susceptibility are conditional estimates, not recorded infections or measured coverage changes following an enacted policy.
According to Mohareb and colleagues, deferral and shared decision-making would increase childhood chronic HBV infections and leave more people susceptible near adulthood relative to universal birth-dose vaccination. The extent of those differences depends on the model's coverage and infection-risk assumptions.
Clinician Questions
What does the projected HBV susceptibility of children entering adulthood each year mean under shared decision-making?
Mohareb and colleagues concluded that, under the proposed shared decision-making changes to hepatitis B vaccination, between 50% and 70% of children entering adulthood annually would remain susceptible to HBV infection. That annual-adulthood proportion is a model projection, not observed US prevalence or another count of chronic infections in the 2026 birth cohort.
Which maternal HBV screening inputs informed the US infant birth-dose projections?
Published inputs included maternal HBV prevalence, reflecting the frequency of maternal infection in the modeled population, and the sensitivity of maternal hepatitis B surface antigen testing, concerning detection of that infection. These distinct inputs informed the projected comparisons among vaccination strategies for US-born infants.