Changes and gaps of global and regional disease burden of hepatitis B infection in children younger than 5 years old between 2015 and 2019: A real-world data review.

Hepatitis B virus (HBV) infection has been declared an ongoing health threat, especially infections among children. We compared and updated the disease burden of HBV infection and the effectiveness of vaccination among children younger than 5 years to offer indications for hepatitis B prevention across the world. The country-level data on the prevalence of hepatitis B surface antigen (HBsAg), the coverages of hepatitis B vaccine birth-dose (HepB-BD), three-dose series (HepB3), income level, population density/size, and human development index were collected from open access databases including WHO, UNICEF, and World Bank. Comparison of the prevalence of HBsAg under 5 years old between 2015 and 2019 based on vaccination coverages was conducted by the gamma generalized linear mixed model. Globally, more than 6.3 million HBV infections were estimated in children under 5 years in 2019, compared to 10.1 million in 2015 within the 179 countries involved. The pooled average prevalence of HBsAg among children younger than 5 years decreased from 1.4% (95% confidence interval [CI]: 1.1-1.8) to 0.9% (95% CI: 0.7-1.2). The rate difference or rate ratio was -0.5% (95% CI: -0.6% to -0.3%) or 0.51(95% CI: 0.44-0.58), respectively. Countries from the African region or with lower income/population density/human development indexes bore the most significant disease burden of hepatitis B. Higher coverages of hepatitis B vaccine birth-dose or primary series correlated with significant HBsAg prevalence decreases and much-decreased ratio, independently. Hepatitis B prevention among children under 5 years has significantly been achieved while remaining the most life-threatening disease burden, unequally distributed worldwide. The hepatitis B vaccination should be prioritized for all newborns, especially in those resource-constrained countries or regions.