TB Research

Global threshold dynamics of a novel TB model with post-exposure vaccination and preventive treatment: China’s roadmap to 2035

Xiaofang Zhao, Caihong Guo, Lianwen Wang, Zhijun Liu

Advances in Continuous and Discrete Models · 2025-11

Abstract

China faces a substantial burden of latent tuberculosis infection (LTBI), with an estimated 30 million potential new tuberculosis (TB) cases likely to emerge in the absence of systematic interventions. While the BCG vaccine provides substantial protection against infantile TB, its efficacy against pulmonary TB in adults varies significantly. Currently, six candidate vaccines aimed at preventing or delaying the progression from LTBI to active TB have advanced to Phase III clinical trials, among which the novel M72/AS01E candidate vaccine elicits a sustained immunogenicity with a protective efficacy of 49.7%. This work develops a TB transmission model that integrates pre-exposure and post-exposure vaccination strategies, TB preventive treatment (TPT) targeting LTBI, and accounts for relapse and incomplete therapy. A comprehensive threshold dynamics analysis for the model is conducted by applying a new analytical method to determine the coefficients of the candidate Lyapunov function and its time derivative. Subsequently, the model proposed is applied to fit the TB cases data in China. Static and dynamic sensitivity analyses reveal that key interventions, including timely isolation and treatment for TB patients, shortened average treatment duration, enhanced TPT for LTBI, and extended vaccine-induced immunity by novel vaccine, could significantly reduce the TB endemic levels. Furthermore, integrated prevention and control strategies are designed to support China’s efforts in achieving the WHO’s End TB Strategy goals by 2035 through numerical simulations.

MeSH terms

  • Medicine
  • Vaccination
  • Tuberculosis
  • Immunogenicity
  • Vaccine efficacy
  • Isolation (microbiology)
  • BCG vaccine
  • Transmission (telecommunications)
  • Tuberculosis vaccines
  • Immunology
  • Clinical trial
  • Intensive care medicine
  • Latent tuberculosis
  • Environmental health