Modelling the impacts of new approaches for TB management

Different diagnostic strategies for tuberculosis (TB) vary in cost-effectiveness depending on local factors such as the prevalence of HIV, drug resistance, and access to health facilities. The discrete-event simulation (DES) tool is particularly valuable for assessing diagnostic methods for multidrug-resistant TB (MDR-TB) in central reference facilities. This tool enables policymakers to evaluate the impact of TB diagnostic tools in resource-limited settings, improving decision-making processes. By incorporating a disease transmission component, the DES model gains enhanced predictive capabilities, offering insights into TB incidence and its effects on health systems and patient outcomes. Furthermore, a visual and interactive DES tool empowers national policymakers to validate diagnostic strategies, explore new approaches, and effectively engage with simulation outcomes.[1]

A study explored the potential impact of introducing novel tuberculosis (TB) vaccines, addressing critical questions about the consequences of delaying vaccine introduction beyond 2025, the health benefits of different rollout strategies, and variations in impact across WHO regions, income levels, and TB burden. Using a dynamic transmission model incorporating epidemiological data and socioeconomic factors, the study found that introducing vaccines, particularly for adolescents and adults, could prevent 44 million TB cases and 5 million deaths by 2050 in the base-case scenario. Accelerated rollouts could further amplify the benefits, averting 65.5 million cases and 7.9 million deaths, with the greatest impact in the African and South-East Asian regions and low-income countries.[2]

The findings highlight the transformative potential of novel TB vaccines, particularly when paired with accelerated rollout strategies. High-efficacy vaccines or those offering lifelong protection could significantly enhance outcomes, saving millions of lives and reducing TB incidence and mortality by up to 27%. Policymakers are urged to prioritize rapid vaccine introductions, modeled on the success of COVID-19 vaccine campaigns, to maximize global health benefits and address the TB burden in high-need regions.[2]

References:

1. Langley, I., Doulla, B., Lin, H.H., Millington, K. and Squire, B., 2012. Modelling the impacts of new diagnostic tools for tuberculosis in developing countries to enhance policy decisions. Health care management science, 15, pp.239-253. 

2. Clark, R.A., Mukandavire, C., Portnoy, A., Weerasuriya, C.K., Deol, A., Scarponi, D., Iskauskas, A., Bakker, R., Quaife, M., Malhotra, S. and Gebreselassie, N., 2023. The impact of alternative delivery strategies for novel tuberculosis vaccines in low-income and middle-income countries: a modelling study. The Lancet Global Health, 11(4), pp.e546-e555.