The potential impact of novel tuberculosis vaccine introduction on economic growth in low- and middle-income countries: A modeling study

BackgroundMost individuals developing tuberculosis (TB) are working age adults living in low- and middle-income countries (LMICs). The resulting disability and death impact economic productivity and burden health systems. New TB vaccine products may reduce this burden. In this study, we estimated the impact of introducing novel TB vaccines on gross domestic product (GDP) growth in 105 LMICs. Methods and findingsWe adapted an existing macroeconomic model to simulate country-level GDP trends between 2020 and 2080, comparing scenarios for introduction of hypothetical infant and adolescent/adult vaccines to a no-new-vaccine counterfactual. We parameterized each scenario using estimates of TB-related mortality, morbidity, and healthcare spending from linked epidemiological and costing models. We assumed vaccines would be introduced between 2028 and 2047 and estimated incremental changes in GDP within each country from introduction to 2080, in 2020 US dollars. We tested the robustness of results to alternative analytic specifications. Both vaccine scenarios produced greater cumulative GDP in the modeled countries over the study period, equivalent to $1.6 (95% uncertainty interval: $0.8, 3.0) trillion for the adolescent/adult vaccine and $0.2 ($0.1, 0.4) trillion for the infant vaccine. These GDP gains were substantially lagged relative to the time of vaccine introduction, particularly for the infant vaccine. GDP gains resulting from vaccine introduction were concentrated in countries with higher current TB incidence and earlier vaccine introduction. Results were sensitive to secular trends in GDP growth but relatively robust to other analytic assumptions. Uncertain projections of GDP could alter these projections and affect the conclusions drawn by this analysis. ConclusionsUnder a range of assumptions, introducing novel TB vaccines would increase economic growth in LMICs. Author summary Why was this study done? Most individuals who develop tuberculosis (TB) are working age adults living in low- and middle-income countries (LMICs), and the resulting disability and death impact economic productivity and burden health systems, but new TB vaccine candidates may reduce this burden.Earlier studies have estimated the impact of individual diseases and health risks on rates of economic growth, but the potential gains to economic growth that could be produced by introducing novel TB vaccines have not been previously estimated. What did the researchers do and find? In this study, we estimated the impact of introducing novel TB vaccines on gross domestic product (GDP) growth in 105 LMICs, using a macroeconomic model to simulate country-level GDP trends between 2020 and 2080, in 2020 US dollars.We compared scenarios for introduction of infant and adolescent/adult vaccine candidates to a no-new-vaccine counterfactual.Compared to the no-new-vaccine counterfactual, both vaccination scenarios produced greater cumulative GDP in the modeled countries over the study period, equivalent to $1.6 (95% uncertainty interval: $0.8, 3.0) trillion for the adolescent/adult vaccine and $0.2 ($0.1, 0.4) trillion for the infant vaccine.These GDP gains were substantially lagged relative to the time of vaccine introduction and concentrated in countries with higher current TB incidence. What do these findings mean? This study demonstrates that introducing new TB vaccines could increase economic growth in LMICs.The results of this research could inform decision-making around how new TB vaccines are developed and introduced.