Trends and disparities in hepatitis B burden in the Western Pacific Region, 2015–2024: a subregional analysis using modelled data

Background The Western Pacific Region (WPR) carries one of the world's largest hepatitis B virus (HBV) burdens, but elimination progress remains uneven. We assessed changes in HBV burden and heterogeneity in elimination progress across the WPR during 2015–2024. Methods We conducted a regional ecological study using standardised modelled estimates from the Center for Disease Analysis Foundation for 34 WPR countries and areas from 2015 to 2024. Country-specific temporal trends were quantified using log-linear regression to estimated annual percentage change (EAPC) with 95% CIs. We assessed incidence–mortality divergence, differences in EAPCs across analytical subregions, associations between vaccination coverage and HBV burden, and sensitivity to influential observations, shared model trajectories, non-linearity, and alternative country classification. Findings Regional HBV prevalence declined from 5.28% (95% UI 4.23–6.34) in 2015 to 4.58% (3.66–5.49) in 2024, and chronic HBV incidence declined from 6.32 to 3.16 per 100,000 population. Under-five prevalence plateaued at approximately 0.28–0.29% from 2019, remaining above the WHO 2030 target of ≤0.1%. Crude modelled HBV mortality increased from 22.88 to 24.70 per 100,000. Of 34 countries and areas, 55.9% had declining chronic incidence alongside increasing mortality. Incidence and mortality EAPCs were modestly correlated (r = 0.39, 95% CI 0.06–0.64; p=0.023), while evidence of systematic differences across analytical subregions was limited. Interpretation Declining HBV incidence has not been accompanied by declining mortality in many WPR countries and areas. Elimination monitoring should therefore assess transmission and mortality as distinct outcomes and account for substantial country-level heterogeneity. Funding World Health Organization.