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

Abstract

Background: Most 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 findings: We 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.

Conclusions: Under a range of assumptions, introducing novel TB vaccines would increase economic growth in LMICs.

Fig 1. Time trends in gains of GDP (in billions, 2020 US dollars) for all modeled countries, due to adolescent/adult and infant novel tuberculosis vaccination (panel A); due to adolescent/adult novel tuberculosis vaccine, by world region (panel B); due to infant tuberculosis vaccine, by world region (panel C).

Note: Panels A, B, and C have different y-axis intervals for readability. AFR, WHO African region; AMR, WHO Region of the Americas; EMR, WHO Eastern Mediterranean region; EUR, WHO European region; GDP, gross domestic product; SEAR, WHO Southeast Asian region; WHO, World Health Organization; WPR, WHO Western Pacific region.

Fig 2. Incremental GDP growth compared to the no-new-vaccine counterfactual in successive 5-year periods from 2026 to 2080 for the adolescent/adult vaccine (panel A) and infant vaccine (panel B).

Note: Boxplots represent the distribution of results across individual countries (point estimates), for each 5-year period. Red lines indicate the arithmetic mean of these values for all countries (solid line) and the 30 countries identified as high-TB-burden by WHO (dashed line). Red shaded regions report 95% uncertainty intervals. Note different y-axis scales. GDP, gross domestic product; TB, tuberculosis; WHO, World Health Organization.

Fig 3. Relationship between additional GDP growth produced by the adolescent/adult vaccine over 2028–2080, current TB incidence level, and vaccine introduction year.

Note: Each point represents point-estimate results for an individual country. Color scale ranges from low percentage increase in GDP relative to other countries (reds) to high percentage increase in GDP relative to other countries (blues). Vaccine introduction year values jittered to display overlapping points. GDP, gross domestic product; TB, tuberculosis.