Cost-benefit analysis of a potential hepatitis C vaccine: a modelling study.
BACKGROUND The increased availability and cost-reduction of curative hepatitis C therapies and global commitments to elimination through treatment scale-up have made the value proposition for a hepatitis C vaccine unclear. This study aimed to estimate the health impact and benefit-cost ratio of a potential hepatitis C vaccine under different use scenarios. METHODS A compartmental model of hepatitis C transmission, disease progression and care cascade was calibrated to 116 countries, with populations stratified by age, sex, injection drug use status and incarceration status. Model inputs were taken from global datasets (e.g. United Nations, Institute of Health Metrics and Evaluation), published academic literature and WHO reports. Scenarios projected for 2026-2050 included: (1) test-treat-vaccinate for people who inject drugs at existing country-specific testing coverage; (2) Scenario 1 plus a one-off test-treat-vaccinate campaign for people who inject drugs; (3) Scenario 2 plus test-treat-vaccinate of prison populations; (4) Scenario 3 plus school-based vaccination; and (5) Scenario 4 plus a five-year adult catch-up campaign. Each scenario's comparator was a counterfactual with equivalent testing and treatment but no vaccine. Only RNA-negative individuals were eligible for the vaccine (i.e. following negative test or post-treatment), and the vaccine was modelled to increase spontaneous clearance rates to 80% for a mean five-year period. Vaccination costs included commodity (assumed US$5 per person in low and lower-middle income settings, with cost ratio of 1:2:15 for upper-middle and high income settings), service delivery and programmatic costs. Benefits included reduced confirmatory testing, treatment, disease management and productivity losses. RESULTS Globally, scenarios 1-5 averted 1.13-8.76 million infections and 2,490-24,100 deaths. Scenarios 1, 2 and 3 had benefit-cost ratios of 2.86, 3.24, and 2.20 respectively. Scenario 4 only had a benefit-cost ratio > 1 for a vaccine with longer duration of protection. Scenario 5 had a benefit-cost ratio < 1 for all characteristics tested. CONCLUSIONS In the context of heterogeneous treatment scale-up among countries, a hepatitis C vaccine is likely to have a positive return-on-investment when used to vaccinate populations at highest risk of infection. TRIAL REGISTRATION Not applicable.