Illustrative combination of interventions to meet the 2030 milestones, in the CAR/EU country group.

Details are as in Fig 2. Under the intervention scenarios shown here, vaccination coverage would need to ensure that 72% of people with TB infection have vaccine-induced immunity, in order to meet the 2030 target.</p

Projected trends when tracking the number-needed-to-test (NNT) to identify 1 person with TB, in the Sub-Saharan Africa country group.

Projected trends when tracking the number-needed-to-test (NNT) to identify 1 person with TB, in the Sub-Saharan Africa country group.</p

Fig 1 -

Comparison of different countries in the USAID portfolio, according to the proportion HIV/TB coinfection (top panel) and the proportion of incident TB that is rifampicin-resistant (bottom panel). Colours denote the different geographic groupings listed in Table 1. For each country group, horizontal dashed lines show average values, when weighted by country population size. The horizontal dotted line shows the population-weighted average over all countries in the portfolio.</p

Pre-COVID calibration data used for each of the country groups.

All data, including uncertainty intervals, were drawn from the WHO global TB database.</p

Interventions modelled for each of the country groups.

As noted in the text, these interventions mirror those modelled in the recent Global Plan to End TB [20]. Assumed levels of coverage are only illustrative, and do not necessarily represent the only possible scenarios for meeting the 2030 End TB goals. With the exception of vaccination, we assumed that all interventions would be initiated in 2022 and scaled up in a linear way over the next three years, to reach the coverage levels shown. For the TB vaccine scenario, we modelled a scenario where a vaccine is licensed by 2025, and scaled up over the subsequent three years.</p

Projected trends when tracking the number-needed-to-test (NNT) to identify 1 person with TB, in the Central Asia/Europe country group.

Projected trends when tracking the number-needed-to-test (NNT) to identify 1 person with TB, in the Central Asia/Europe country group.</p

Illustrative combination of interventions to meet the 2030 milestones, in the South Asia country group.

Interventions are shown in successive combination so that the bottom curve in each panel, for example, shows all interventions (including vaccination) acting together. As described in the main text, we assumed that vaccination is implemented from 2025 onwards, and that all other interventions are implemented from 2022 onwards. The horizontal, dashed line shows the target for incidence reduction by 2030. Under the intervention scenarios shown here, vaccination coverage would need to ensure that 72% of people with TB infection have vaccine-induced immunity, in order to meet the 2030 target.</p

Projected trends when tracking the number-needed-to-test (NNT) to identify 1 person with TB, in the South Asia country group.

Shown are three different examples of NNT: when monitoring patients being tested in routine TB care settings (left-hand panel); amongst those with symptoms who are screened as part of active case-finding (middle panel); and amongst all persons tested in active case-finding where eligibility is not restricted to those with symptoms (right-hand panel). As in Figs 2–4, all interventions are shown in cumulative combination, e.g. with the purple curve showing all interventions acting together.</p

Illustrative combination of interventions to meet the 2030 milestones, in the Sub-Saharan Africa country group.

Details are as in Fig 2. Under the intervention scenarios shown here, vaccination coverage would need to ensure that 40% of people with TB infection have vaccine-induced immunity, in order to meet the 2030 target.</p

Additional technical details, figures and tables.

Progress towards the 2030 End TB goals has seen severe setbacks due to disruptions arising from the COVID-19 pandemic. For governments and international partner organizations supporting the global TB response, there is a need to assess what level of effort is now needed to reach these goals. Using mathematical modelling, we addressed this question for the countries being supported by the United States Agency for International Development (USAID). We aggregated the 24 countries in the USAID portfolio into three geographical country groups: South Asia; sub-Saharan Africa; and Central Asian Republics/Europe (CAR/EU). From 2023 onwards we modelled a combination of interventions acting at different stages of the care cascade, including improved diagnostics; reducing the patient care seeking delay; and the rollout of a disease-preventing vaccine from 2025 onwards. We found that in all three country groups, meeting the End TB goals by 2030 will require a combination of interventions acting at stages of the TB care cascade. Specific priorities may depend on country settings, for example with public-private mix playing an important role in countries in South Asia and elsewhere. When a vaccine becomes available, its required coverage to meet the 2030 goals will vary by setting, depending on the amount of preventive therapy that has already been implemented. Monitoring the number-needed-to-test to identify 1 person with TB in community settings can provide a useful measure of progress towards the End TB goals.</div