Health and economic impacts of Vaccae vaccination incorporating active case finding in India and South Africa: a modelling study

Abstract

IntroductionTuberculosis (TB) is a major global health issue, particularly, in India and South Africa. We aim to evaluate the potential of the new TB vaccine, Vaccae, to enhance TB control by integrating with active case finding (ACF) strategies in these regions.MethodsUsing age-structured dynamic models, we projected the epidemiological and economic outcomes of combining Vaccae vaccination with ACF over 27 years. In India, four age-targeted strategies were analysed: (1) adolescent (15 years), (2) adolescent and young adult (AYA, 15–34 years), (3) adult (18–55 years) and (4) elderly (60+ years). In South Africa, strategies were based on HIV status: (1) HIV-targeted, (2) non-HIV and (3) general population. The vaccine efficacy of Vaccae was set at 54.7%, priced at US$120 per course. Outcomes measured included reductions in TB incidence and mortality, prioritised based on budget, incremental cost-effectiveness ratios (ICER) and benefit-cost ratios (BCR).ResultsIn India, the adult strategy could prevent 8.70 (95% UI: 6.86–11.13) million TB cases and 0.61 (0.39–0.91) million deaths, reducing incidence and mortality by 20.1% (18.7%–23.5%) and 19.0% (17.5%–22.5%), respectively. In South Africa, the general population strategy could avert 0.67 (0.45–0.99) million TB cases and 0.21 (0.15–0.28) million deaths, reducing incidence by 28.1% (26.1%–30.3%) and mortality by 27.0% (23.5%–30.0%). The vaccination budgets for the AYA strategy in India and the HIV-targeted strategy in South Africa were US$14.0 (10.14–23.29) billion and US$0.09 (0.06–0.15) billion, respectively. The ICERs were US$1082 (927–1426) and US$70 (53–123) per disability-adjusted life year averted, and the BCRs were 2.0 (1.6–2.4) and 176 (83.4–255.3), respectively. Thus, the AYA strategy in India and the HIV-targeted strategy in South Africa were the most favourable.ConclusionIntegrating Vaccae vaccination with ACF could significantly enhance TB control in high-burden countries. Policymakers should consider these strategies, with further research needed to confirm the findings.