Explained: What’s at stake in India’s biggest ever trial of tuberculosis vaccines

Treating TB requires a multi-drug course of treatment lasting six months; longer still for treating drug-resistant TB. Treatment failure and recurrence can have devastating consequences.

icmr new tuberculosis vaccines, Indian Council of Medical Research, ICMR new tb vaccines, tb vaccines,

India contributes to 27 per cent of the global TB burden; the highest share globally. (Source: File Photo)

On July 15, the Indian Council of Medical Research (ICMR) launched India’s first large-scale trial for two new tuberculosis (TB) vaccines.

As per the 2018 annual report of the Central TB division of Ministry of Health and Family Welfare, the incidence of TB was nearly 2.8 million annually, and the incidence of multidrug-resistant TB was 1,47,000 per year. The total number of deaths because of TB (excluding HIV) was 4,23,000, and the incidence of HIV-TB was 87,000 per year. India contributes to 27 per cent of the global TB burden; the highest share globally. That is why, in 2017, the central government had committed itself to eliminating TB by 2025.

The new vaccines that are being put through the trials offer a chance to contain the accelerating spread of multi-drug resistant TB. Treating TB requires a multi-drug course of treatment lasting six months; longer still for treating drug-resistant TB. Treatment failure and recurrence can have devastating consequences.

Why new vaccines

Scientists at the Indian Council of Medical Research have felt a critical need for new TB vaccines that are more effective than the Bacille Calmette-Guerin (BCG) vaccine. The BCG vaccine is used in the routine Expanded Programme of Immunisation (EPI) in countries across the world. It is generally given at birth or in the first year. The vaccine is over 100 years old and, while it has been partially effective in protecting infants and young children, particularly from the most severe forms of TB, it provides poor protection against pulmonary disease in adolescents and adults.

It is for these reasons a need was felt to develop more effective preventive TB vaccines, Dr Balram Bhargava, Director General of ICMR, said.

Which vaccines

There are two vaccines being tested in the latest trial: Immuvac (also known as mycobacterium indicus pranii or MIP), which is manufactured by Cadila Pharmaceuticals in Ahmedabad, and VPM1002 manufactured by Serum Institute of India in Pune. There are seven main centres with six subsites where the trial will be conducted.

What the latest trials entail

Typically, vaccine trials have three phases. During Phase 1, small groups of people receive the trial vaccine. In Phase 2, the clinical study is expanded and the vaccine is given to people who have characteristics (such as age and physical health) similar to those for whom the new vaccine is intended. In Phase 3 the vaccine is given to several thousands of people and tested for efficacy and safety.

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Even so, India’s trials stand out. Dr Manjula Singh, co-investigator and coordinator of the vaccine trial said that nowhere has a Phase 3 trial involved trying out two TB vaccines in one go. This is the first time that such a large preventive TB vaccine trial has been taken up.

The trials in India will involve enrolling 12,000 healthy household contacts of newly diagnosed pulmonary TB patients. The candidates will be enrolled from across six states — Delhi, Maharashtra, Telangana, Odisha, Karnataka and Tamil Nadu. Approximately 2,000 participants will be enrolled in each state over the next 7-8 months. The main aim of the trial is to evaluate the efficacy of both the vaccines by comparing the reduction in the incidence of TB over a three-year period. The candidates in this trial will be at high risk of contracting the disease, and will be vaccinated in a double-blind manner with either one of the vaccines, and compared with placebo for its efficacy.

What happens next

This is a Phase 3 vaccine trial where the safety and efficacy of the two TB vaccines are being studied in comparison to the placebo in a larger population.

Depending on the results, the recommendations would be sent to the Union Ministry of Health and Family Welfare. Both vaccines are being manufactured by Indian pharmaceutical companies. The price of the vaccines would be decided by the government.

Anuradha Mascarenhas

Anuradha Mascarenhas is a Senior Editor at The Indian Express, based in Pune. With a career spanning three decades, she is one of the most respected voices in Indian journalism regarding healthcare, science and environment and research developments. She also takes a keen interest in covering women's issues . Professional Background Education: A gold medalist in Communication and Journalism from Savitribai Phule Pune University and a Master’s degree in Literature. Author: She authored the biography At The Wheel Of Research, which chronicles the life and work of Dr. Soumya Swaminathan, the former Chief Scientist at the WHO. Key Focus: She combines scientific accuracy with storytelling, translating complex medical research into compelling public and human-interest narratives. Awards and Recognition Anuradha has won several awards including the Press Council of India's national award for excellence in journalism under the gender based reporting category in 2019 and the Laadli Media award (gender sensitivity -2024). A recipient of the Lokmat journalism award (gender category-2022), she was also shortlisted for the RedInk awards for excellence in journalism-2021. Her debut book At The Wheel Of Research, an exclusive biography of Dr Soumya Swaminathan the inaugural chief scientist of World Health Organisation was also nominated in the Popular Choice Category of JK Paper AUTHER awards. She has also secured competitive fellowships including the Laadli Media Fellowship (2022), the Survivors Against TB – New Research in TB Media Fellowship (2023) and is part of the prestigious 2025 India Cohort of the WomenLift Health Leadership Journey.” Recent Notable Articles (Late 2025) 1. Cancer & Specialized Medical Care "Tata Memorial finds way to kill drug-resistant cancer cells" (Nov 26, 2025): Reporting on a breakthrough for triple-negative breast cancer, one of the most aggressive forms of the disease. Discipline, diet and purpose; How a 97-year-old professor defies ageing'' (Nov 15, 2025) Report about Prof Gururaj Mutalik, the first Head of Department at Pune's B J Government Medical College who at 97 credits his longevity to healthy habits and a strong sense of purpose. 2. Environmental Health (The "Breathless Pune" Series) Long-term exposure even to 'moderate' air leads to chronic heart, lung, kidney issues" (Nov 26, 2025): Part of an investigative series highlighting that even "safe" pollution levels are damaging to vital organs. "For every 10 µg/m3 increase in PM2.5 level, there was 6-8% jump in medicine sales" (Nov 23, 2025): Using commercial data to prove the direct link between air quality and respiratory illnesses in Pune. 3. Lifestyle & Wellness News "They didn't let cancer, diabetes and heart disease stop them from travelling" (Dec 22, 2025): A collaborative piece featuring survivors who share practical tips for traveling with chronic conditions. At 17, his BP shot up to 200/120 mmHG; Lancet study flags why child and teen hypertension doubled between 2000 and 2020'' (Nov 12,2025)--A report that focusses on 17-year-old-boy's hypertensive crisis and reflects the rising global trend of high blood pressure among children and adolescents. 4. Scientific Recognition & Infrastructure For promoting sci-comm, gender diversity: IUCAA woman prof highlighted in Nature" (Nov 25, 2025): Covering the global recognition of Indian women scientists in gender studies and physics. Pune researchers find a spiral galaxy like the Milky Way from early universe'' (December 3, 2025)- A report on how Indian researchers discovered a massive galaxy that existed when the universe was just 1.5 billion years old , one of the earliest to have been observed so far. Signature Beat: Health, Science & Women in Leadership Anuradha is known for her COVID-19 reportage, where she was one of the first journalists to provide detailed insights into the Covishield and Covaxin trials. She has a dedicated interest in gender diversity in health and science, often profiling women researchers who are breaking the "leaky pipeline" in STEM fields. Her writing style is scrupulous, often featuring interviews with top-tier scientists and health experts from various institutions. ... Read More