Article Text
Abstract
Introduction Despite the availability of a safe and effective vaccine and treatment against hepatitis B, variability of coverage means that HBV still accounts for up to one million deaths annually worldwide. Our aim was to evaluate and support the potential impact of scaling up interventions against HBV, set realistic targets for elimination of transmission and mortality due to HBV and identify key developments needed to achieve them.
Method A dynamic, age, sex and region-structured mathematical model of the worldwide HBV epidemic was constructed incorporating data on epidemiology, vaccination coverage, treatment, regional demography and the natural history of HBV. The model was used to generate predictions regarding incidence of new chronic HBV infections, prevalence and HBV related mortality under assumptions that interventions remain at current levels (‘status quo’). We then used the model to estimate the impact of scaling up of both prevention and treatment interventions, to establish what would be sufficient to bring HBV to the threshold of control and elimination by 2030.
Results The scale-up of infant HBV vaccination to date, is already driving a decrease in new infections, and if maintained at current levels, will have averted 1.2 M deaths by 2030. This will also result in a greater proportion of transmission being mother-to-child. Without further intervention, the number of persons living with HBV will remain at the same current high levels for the next 40–50 years and there will be 20 M HBV-related deaths by 2030. However, a 90% reduction in incidence of new chronic infections and 65% reduction in mortality could be achieved by 2030 with the scale-up of existing interventions: >95% coverage of infant vaccination, 80% coverage of birth dose vaccine and 73% coverage of treatment for all those eligible (implemented from c. 2020). This would amount to 13 M deaths averted worldwide by 2030, including 6 M cases of cancer. The global cost is forecast to peak at $7.5 B annually but decline rapidly after 2030, and could be accelerated if a cure is developed.
Conclusion The fight against HBV through universal infant vaccination has scored major victories in reducing new infections in some settings but, without further intervention, prevalence and mortality will remain high for decades. However, expansion of vaccination and treatment could reduce deaths by 65% and transmission by 90%. Although the costs are high, they peak at lower values and decline more rapidly than those projected for other infectious diseases with similar burden.
Disclosure of interest None Declared.