India TB: Can vaccines help India triumph over tuberculosis?

In 2018, India ambitiously pledged to eradicate pulmonary tuberculosis (TB) by 2025, five years ahead of the deadline set by the United Nations' Sustainable Development Goals. Prime Minister Narendra Modi reaffirmed this commitment at the One World TB Summit in March 2023. However, the World Health Organization's (WHO) Global Tuberculosis Report paints a grim picture, stating that one person succumbs to the disease in India every two minutes.

The report further reveals that India bore the highest global TB burden in 2022, accounting for 27% of the 10. 6 million people diagnosed with the infection. The country is also home to 47% of individuals who developed multi-drug resistant infection, which is unresponsive or resistant to at least two of the first line of anti-TB drugs. While testing and treatment are the primary methods to combat the disease, India has also invested in the development of an effective TB vaccine. Since 2019, scientists have been testing two potential vaccines in seven research centres.

However, the development of a TB vaccine is fraught with challenges. Dr Marcel A Behr, director of infectious diseases division at Canada's McGill University Health Centre, explains that the lack of a fundamental understanding of how humans resist the TB bacteria makes it difficult to engineer a vaccine. The current test for TB cannot distinguish between a current and past infection, further complicating the quest for a vaccine. Despite these challenges, scientists at the Indian Council of Medical Research (ICMR) have been observing household contacts of TB patients for four years to determine whether they have developed TB.