The fight against tuberculosis (TB) has taken a major step forward as the first patients receive doses in a Phase IIb trial of a new vaccine candidate, MTBVAC. Led by international research organization IAVI and Spanish biopharmaceutical company Biofabri, this randomized, placebo-controlled trial, known as IMAGINE, aims to evaluate the vaccine’s efficacy in preventing TB disease in individuals with latent infections.
The trial will enroll approximately 4,300 adolescent and adult participants who have tested positive for latent TB infections using an interferon gamma release assay (IGRA) test. It will take place across 15 sites in South Africa, Kenya, and Tanzania, targeting a population that remains vulnerable to TB despite existing vaccination efforts.
Since its introduction in 1921, the Bacillus Calmette-Guérin (BCG) vaccine has been the only approved TB vaccine. While it provides some protection, particularly in children, its effectiveness wanes over time and offers limited defense against TB in adults. The BCG vaccine is derived from Mycobacterium bovis, the bovine form of TB. In contrast, MTBVAC is a live-attenuated vaccine developed from Mycobacterium tuberculosis, the bacterium responsible for human TB.
Previous research has shown promising results for MTBVAC. A Phase II trial investigated its use in newborns, and Biofabri is currently conducting a Phase III study in neonates across South Africa, Madagascar, and Senegal. Additionally, a study published in Nature found that the vaccine provided significantly improved protection in rhesus macaques following aerosol exposure to M. tuberculosis, compared to a single dose of BCG.
Experts involved in the trial have highlighted the urgent need for a more effective TB vaccine, particularly in regions with high infection rates. The disease remains one of the leading causes of death worldwide, with the World Health Organization (WHO) estimating that 1.25 million people died from TB in 2023. In addition to its devastating impact on health, TB also poses significant economic challenges for low- and middle-income countries, where it disproportionately affects young, working-age populations.
A key advantage of MTBVAC is its single-dose regimen, which could simplify immunization efforts, especially in hard-to-reach areas. If proven effective, the vaccine has the potential to prevent millions of TB cases and reduce transmission rates significantly.
Despite progress in TB research, concerns remain about funding. Some programs have relied on support from agencies such as the US Agency for International Development (USAID), which has recently cut funding for TB initiatives. Researchers have warned that alternative sources, including private foundations and governmental organizations, will be necessary to maintain momentum in vaccine development and TB treatment advancements.
In other TB-related developments, advancements in medical artificial intelligence have shown promise in improving diagnosis. AI-driven chest X-ray analysis software, such as Lunit’s INSIGHT CXR, has demonstrated superior accuracy in detecting TB, potentially enhancing early diagnosis and treatment strategies.
With trials like IMAGINE and innovations in AI diagnostics, efforts to combat TB are progressing. However, continued investment and global collaboration will be critical to achieving lasting success in the fight against this infectious disease.
