The impact of alternative delivery strategies for novel tuberculosis vaccines in low- and middle-income countries: a modelling study

Background Tuberculosis is a leading infectious cause of death worldwide. Novel vaccines will be required to reach global targets and reverse setbacks from the COVID-19 pandemic. We estimated the impact of novel tuberculosis vaccines in low- and middle-income countries (LMICs) under alternative delivery scenarios. Methods We calibrated a tuberculosis model to 105 LMICs (93% of global tuberculosis incidence). Vaccine scenarios were implemented as Basecase : routine vaccination of 9-year-olds and a one-time vaccination campaign for ages ≥10 with country-specific introduction between 2028–2047 and 5-year scale-up to target coverage; Accelerated Scale-up : as Basecase , but all countries introducing in 2025 with instant scale-up; and Routine Only : as Basecase , but routine vaccination only. Vaccines protected against disease for 10-years, with 50% efficacy. Findings The Basecase scenario prevented 44.0 (95% uncertainty range=37.2–51.6) million tuberculosis cases, and 5.0 (4.6–5.4) million tuberculosis deaths before 2050, including 2.2 million in the WHO South-East Asian region. The Accelerated Scale-up scenario prevented 65.5 (55.6–76.0) million cases and 7.9 (7.3–8.5) million deaths before 2050. The Routine Only scenario prevented 8.8 (7.6–10.1) million cases and 1.1 (0.9–1.2) million deaths before 2050. Interpretations Novel tuberculosis vaccines could have substantial impact, which will vary depending on delivery strategy. Including a campaign will be crucial for rapid impact. Accelerated introduction, more similar to the pace of COVID-19 vaccines, could increase lives saved by around 60%. Investment is required to support vaccine development, manufacturing, prompt introduction and scale-up. Funding WHO (2020/985800-0) ### Competing Interest Statement RCH reports employment by Sanofi Pasteur, unrelated to tuberculosis and outside the submitted work. All other authors declare no conflicts of interest. ### Funding Statement We are grateful for the support of the World Health Organization for funding this research (2020/985800-0). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes Analytic code will be made available at https://doi.org/10.5281/zenodo.6421372 immediately following publication indefinitely for anyone who wishes to access the data for any purpose.