Application of sero- epidemiology data to inform interventions for HBV in Africa: should diagnosis and treatment replace catch-up vaccination?

Abstract

International goals for hepatitis B virus (HBV) infection set ambitious targets for elimination by 2030. In populations with a high prevalence of infection, catch-up HBV vaccination of adults is sometimes deployed. An alternative approach of ‘test and treat’ could be applied as a population intervention for HBV. Methods: We used a systematic approach to determine the relationship between prevalence of HBV infection (HBsAg) and exposure (anti-HBc) in Africa. We applied a mathematical model to compare the impact of catch-up vaccination with a ‘test and treat’ strategy in a high prevalence setting. Findings: There is a strong relationship between the prevalence of HBsAg and antiHBc (p<0·0001) across Africa, but the pattern differs between regions. Our data can be interactively visualised at https://hbv-geo.shinyapps.io/oxafricahbv/. In settings with high prevalence of infection, catch-up vaccination may have a transient effect. However, this intervention does not contribute to a sustained decline in prevalence, because a high proportion of adults are either already infected or immune as a result of prior exposure. In contrast, diagnosing and treating infection has a marked impact on reducing prevalence, equivalent to that of neonatal vaccination. Interpretation: We have developed a high-resolution picture of HBV epidemiology across Africa. In combination with robust neonatal vaccination programmes, testing and treating infection is likely to be of more benefit than catch-up vaccination. This alternative not only benefits the infected individual, but also has impact on transmission, thus contributing to sustained reductions in population prevalence.