The potential impact of novel tuberculosis vaccines on health equity and financial protection in low-income and middle-income countries

Abstract

Introduction: One in two patients developing tuberculosis (TB) in low-income and middle-income countries (LMICs) faces catastrophic household costs. We assessed the potential financial risk protection from introducing novel TB vaccines, and how health and economic benefits would be distributed across income quintiles.

Methods: We modelled the impact of introducing TB vaccines meeting the World Health Organization preferred product characteristics in 105 LMICs. For each country, we assessed the distribution of health gains, patient costs and household financial vulnerability following introduction of an infant vaccine and separately for an adolescent/adult vaccine, compared with a 'no-new-vaccine' counterfactual. Patient-incurred direct and indirect costs of TB disease exceeding 20% of annual household income were defined as catastrophic.

Results: Over 2028-2050, the health gains resulting from vaccine introduction were greatest in lower income quintiles, with the poorest 2 quintiles in each country accounting for 56% of total LMIC TB cases averted. Over this period, the infant vaccine was estimated to avert US$5.9 (95% uncertainty interval: US$5.3-6.5) billion in patient-incurred total costs, and the adolescent/adult vaccine was estimated to avert US$38.9 (US$36.6-41.5) billion. Additionally, 3.7 (3.3-4.1) million fewer households were projected to face catastrophic costs with the infant vaccine and 22.9 (21.4-24.5) million with the adolescent/adult vaccine, with 66% of gains accruing in the poorest 2 income quintiles.

Conclusion: Under a range of assumptions, introducing novel TB vaccines would reduce income-based inequalities in the health and household economic outcomes of TB in LMICs.

Keywords: health economics; tuberculosis; vaccines.

Figure 1

Tuberculosis (TB) cases averted (A) and number of households with catastrophic costs averted (B) by within-country income quintile comparing infant vaccine to adolescent/adult vaccine. Note: The total cost of a TB episode presented here included patient direct medical, direct non-medical and indirect costs over 2028–2050. Total costs borne by TB-affected households are categorised as ‘catastrophic’ if they exceed 20% of total household’s annual income.

Figure 2

Cases of tuberculosis over time and by income quintile with delivery of adolescent/adult tuberculosis vaccines across 105 low-income and middle-income countries. Note: Country-specific vaccine introduction years from 2028 to 2047.

Figure 3

Distribution of tuberculosis cases averted (A) and number of households experiencing catastrophic costs averted over 2028–2050 (B) by an adolescent/adult vaccine across all modelled strata, ordered by household income. CC, catastrophic costs; GDP, gross domestic product; TB, tuberculosis. Bars defined by left-hand side y-axis; lines defined by right-hand side y-axis. Ordering of population by household income based on average 2020 per capita GDP in purchasing power parity (PPP) dollars, for each modelled stratum (525 total strata). Bars shaded red indicate the poorest 20% of modelled population by PPP GDP per capita.