Estimating the potential health and economic impacts of new tuberculosis vaccines under varying delivery strategies in Delhi and Gujarat, India: a modelling study.

BACKGROUND: India has the largest tuberculosis burden, but the all-age prevalence in 2021 ranged from 747/100,000 in Delhi to 137/100,000 in Gujarat. No modelling studies have compared the potential impact of new tuberculosis vaccines in regions with differing disease and infection prevalence. METHODS: We used modelling to simulate hypothetical scenarios of introducing M72/AS01E (with 50% efficacy to prevent disease) and BCG-revaccination (with 45% efficacy to prevent infection) in Delhi and Gujarat. FINDINGS: The hypothetical M72/AS01E scenario could avert 16.0% of cases and 14.4% of deaths in Delhi, and 8.5% of cases and 7.6% of deaths in Gujarat between 2025 and 2050. The hypothetical BCG-revaccination scenario could avert 8.8% of cases and 8.3% of deaths in Delhi, and 5.1% of cases and 4.8% of deaths in Gujarat between 2025 and 2050. INTERPRETATION: Additional trials for both vaccines are underway, which will provide further evidence on the vaccine efficacy and narrow the range of uncertainty on the estimates. FUNDING: Bill & Melinda Gates Foundation (INV-001754).