FIGURE 1.

WHO target characteristics for therapeutic tuberculosis vaccines. In order to guide research and development, the WHO has set aspirational targets/characteristics for candidate therapeutic TB vaccines. These include three major areas to address (orange boxes): Vaccine targets that determine efficacy, the target population, and the subsequent long-term impact on the chemotherapy regimen. Candidates which meet some/all of these targets must also be safe, efficacious in a minimum number of repeated doses, and investigated to define their mechanism-of-action or potential efficacy biomarkers, to further refine/guide future vaccination strategies (green boxes).