Use of DNA BCG vaccine with chemotherapy for tuberculosis can be beneficial for treating drug resistant tuberculosis

Tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium tuberculosis bacteria.  TB is one of the leading causes of death worldwide. A third of the world’s population is infected with TB, and the disease is treated with four drugs for two months and two drugs in the continuation phase. When a patient fails to adhere to the prescribed medications, drug resistant mutant bacteria develop within the patient’s lungs. However, the majority of the population is vaccinated against TB using the BCG vaccine, which is derived from the bacteria that causes tuberculosis in cattle. This vaccination is not lifelong and wanes with time. Drug-resistant tuberculosis (DR-TB) currently poses a new threat to global health. This calls for improvement of the treatment outcomes in patients infected with tuberculosis. Therapeutic vaccines along with anti-tuberculosis drugs have been proposed as a way to counteract drug-resistant tuberculosis. Researchers from the University of Embu and Chinese Academy of Sciences examined whether a combination of BCG DNA vaccine and chemotherapy could improve tuberculosis treatment outcome. We tested the therapeutic efficacy of a BCG DNA vaccine when used along with chemotherapy based on tuberculosis drug-resistant mouse models. We observed that the BCG DNA vaccine lowered lung M. tuberculosis burden and minimized lung tissue pathology in the mice with no notable side effects. We concluded that the BCG DNA vaccine complemented chemotherapy in lowering the lung M. tuberculosis bacteria burden. These findings imply that the BCG DNA vaccine could help patients from TB reinfection or disease relapse which is very common among previously treated patients. Our research suggests that adding a DNA BCG vaccine to the chemotherapy for tuberculosis can be beneficial for treating drug resistant tuberculosis.

This article is a summary of a published paper entitled ‘‘A recombinant selective drug-resistant M. bovis BCG enhances the bactericidal activity of a second-line anti-tuberculosis regimen’’ published in Biomedicine & Pharmacotherapy and available via the link:

https://www.sciencedirect.com/science/article/pii/S0753332221008301