TB Vaccines VPM1002, Immuvac Safe but Fall Short in Phase 3 Trial

Two New TB Vaccines Prove Safe but Fall Short of Broad Protection in Large India Trial

The Phase 3 PreVenTB study of more than 12,000 people found the vaccines helped only certain groups against certain forms of tuberculosis — underscoring how hard a better TB shot remains.

By iPharmag Editorial Desk · Aug 24, 2026 · 1 min read

Conceptual illustration of lungs, TB bacteria and a vaccine vial

Conceptual illustration. Two TB vaccines proved safe but fell short of broad protection in a large India trial.

Two new tuberculosis vaccines are safe but do not offer broad protection against all forms of the disease, according to a large Phase 3 trial in India — a sobering result in the century-long effort to improve on the aging BCG shot.

The PreVenTB trial, run by the Indian Council of Medical Research (ICMR), tested VPM1002 and Immuvac (based on Mycobacterium indicus pranii) against placebo in 12,717 household contacts of TB patients (aged 6 and up) across 18 sites in 6 Indian states, with a 38-month follow-up. Results were published in The BMJ (2026).

Who was protected — and who wasn’t

The picture was mixed. VPM1002 showed about 50.4% effectiveness against extrapulmonary TB overall, rising to 79.5% in adults aged 36–60, and protected across all TB forms in children aged 6 to under 14. Immuvac protected only against extrapulmonary TB in children aged 6 to under 10. Notably, neither vaccine protected underweight individuals — a major limitation in populations where TB and undernutrition overlap.

Why it matters

Tuberculosis is among the world’s deadliest infectious diseases, and BCG — the only licensed TB vaccine — offers limited protection in adults. A shot that reliably prevents TB across all forms and populations remains elusive. These results add useful data (and some protective signals in specific groups) but fall short of the broad, robust protection the field is chasing.

Frequently asked questions

Did the TB vaccines work at all?

They were safe and showed protection in specific groups — for example, VPM1002 against extrapulmonary TB, especially in adults 36–60 and in children. But they did not provide broad protection across all forms of TB or all populations, and neither protected underweight people.

Why do we need new TB vaccines?

BCG, the only licensed TB vaccine, offers limited protection in adults. Tuberculosis remains one of the deadliest infectious diseases, so a vaccine that reliably prevents it across populations is a major global-health goal.

This article is for general information only and is not medical advice. Consult a qualified healthcare professional for any medical decisions.