Modelling the prevalence of hepatitis B towards eliminating it as a major public health threat in China.

BACKGROUND: The World Health Organization (WHO) requires reduction in the prevalence of hepatitis B virus (HBV) surface antigen (HBsAg) in children to 0.1% by 2030, a key indicator for eliminating viral hepatitis as a major public health threat. Whether and how China can achieve this target remains unknown, although great achievements have been made. We aimed to predict the decline of HBsAg prevalence in China and identify key developments needed to achieve the target. METHODS: An age- and time-dependent dynamic compartmental model was constructed based on the natural history of HBV infection and the national history and current status of hepatitis B control. The model was run from 2006 to 2040 to predict the decline of HBsAg prevalence under three scenarios including maintaining current interventions (status quo), status quo + peripartum antiviral prophylaxis (PAP, recommended by WHO in 2020), and scaling up current interventions + PAP. RESULTS: Under the status quo, HBsAg prevalence would decrease steadily in all age groups, but the WHO's target of 0.1% prevalence in children aged < 5 years would not be achieved until 2037. The results are robust according to sensitivity analyses. Under the status quo + PAP, the HBsAg prevalence of children aged < 5 years would significantly decrease with the introduction of PAP, and the higher the successful interruption coverage is achieved by PAP, the more significant the decline. However, even if the successful interruption coverage reaches 90% by 2030, the 0.1% prevalence target would not be met until 2031. Under the scaling up current interventions + PAP, combined with scale-up of current interventions, the WHO's 0.1% target would be achieved on time or one year in advance if PAP is introduced and the successful interruption coverage is scaled up to 80% or 90% by 2030, respectively. CONCLUSIONS: It is difficult for China to achieve the WHO's target of 0.1% HBsAg prevalence in children by 2030 by maintaining current interventions. PAP may play an important role to shorten the time to achieve the target. A comprehensive scale-up of available interventions including PAP will ensure that China achieves the target on schedule.