The First New TB Vaccine in a Century Is Almost Here
Every tuberculosis vaccine given since 1921 has been the same one. A candidate now in its final trial could finally end that streak, if the results hold up.
Tuberculosis remains the world's leading cause of death from a single infectious disease. In 2024, an estimated 1.23 million people died from TB worldwide, including 150,000 people living with HIV.
For more than a century, the world has relied on one licensed TB vaccine: BCG, introduced in 1921.
BCG provides important protection against severe forms of TB in infants and young children. But its protection against pulmonary TB in adolescents and adults is limited and variable, the very groups responsible for most TB transmission.
Now, a candidate called M72/AS01E is in a global Phase 3 trial.
An earlier trial produced a promising result: nearly 50% efficacy against active pulmonary TB in a specific group of TB-infected, HIV-negative adults.
And in July 2026, the Serum Institute of India agreed to invest more than US$100 million to prepare manufacturing capacity before those final results are known.
That's the unusual part.
The world is preparing to manufacture a vaccine that hasn't yet proved itself in its final trial.
A Vaccine Frozen in 1921
BCG's limitations aren't a secret.
Developed at the Institut Pasteur between 1908 and 1921, BCG remains the only licensed tuberculosis vaccine. It has played an important role in preventing severe TB, particularly tuberculosis meningitis and disseminated TB in young children.
What it does not reliably provide is strong protection against pulmonary TB in adolescents and adults.
That matters enormously.
Adults and adolescents account for the majority of TB transmission, so a vaccine that could prevent pulmonary disease in these groups could have a much larger effect on the global epidemic.
The gap has remained open for more than 100 years.
Not because researchers stopped trying.
Because tuberculosis is an unusually difficult disease to vaccinate against.
Did You Know?
Tuberculosis is caused by a bacterium, Mycobacterium tuberculosis, rather than a virus.
The bacterium can establish an infection that remains dormant for years before progressing to active disease.
That creates a particularly difficult vaccine target: researchers aren't simply trying to stop an infection from entering the body. They also want to prevent an existing infection from progressing into active, transmissible disease.
WHO estimates that roughly 5–10% of people infected with TB bacteria eventually develop TB disease, although the risk is substantially higher for people with certain health and immune related risk factors.
A Candidate With Real, If Partial, Results
The vaccine now closest to potentially changing this picture is M72/AS01E.
The candidate was developed with support from GSK and later advanced into late-stage development by the Gates Medical Research Institute.
Its most important evidence so far comes from a Phase 2b trial involving 3,575 participants.
But there's an important detail that often gets lost in headlines.
The participants were HIV-negative adults aged 18–50 who already had evidence of TB infection. The study was designed to determine whether the vaccine could prevent that infection from progressing to active pulmonary tuberculosis.
After three years of follow-up, the final analysis found 49.7% vaccine efficacy against active pulmonary TB in the according-to-protocol analysis.
In simpler terms:
The vaccinated group developed active TB at roughly half the rate seen in the placebo group.
That's a significant result.
But it isn't the final answer.
The Trial That Matters Most Is Still Underway
M72/AS01E is now being tested in a much larger Phase 3 trial.
The trial reached full enrollment in April 2025, with approximately 20,000 adolescents and adults across 54 sites in South Africa, Kenya, Malawi, Zambia, and Indonesia.
Participants are being followed for several years to determine whether the vaccine can safely and effectively prevent pulmonary TB.
And this distinction matters:
The roughly 50% efficacy figure comes from the Phase 2b trial. It is not a Phase 3 result.
The Phase 3 results have not yet been reported.
Until they are, nobody can say that M72/AS01E works at the population level or that it will ultimately be approved.
Betting on a Vaccine Before the Results Are In
That's what makes the July 2026 announcement unusual.
The Serum Institute of India, one of the world's largest vaccine manufacturers, reached an agreement with the Gates Medical Research Institute to manufacture M72/AS01E if the vaccine ultimately succeeds and receives regulatory approval.
The Serum Institute expects to invest more than US$100 million of its own resources to strengthen manufacturing readiness and capacity.
Why start before the final results?
Because manufacturing vaccines at global scale takes time.
If the Phase 3 trial succeeds, regulators approve the vaccine, and countries decide to use it, manufacturers would ideally already be preparing production rather than starting from zero.
So this isn't a declaration that the vaccine works.
It's a calculated bet on being ready if it does.
And that distinction is crucial.
WHO says that no new TB vaccine has been licensed in more than a century.
That doesn't mean researchers have been standing still.
As of recent WHO assessments, multiple TB vaccine candidates are in clinical development, with several in late-stage trials. M72/AS01E is one of the leading candidates being studied for adolescents and adults.
If successful, M72/AS01E could therefore become the first new TB vaccine in more than 100 years.
Why This Matters Beyond One Vaccine
TB remains heavily concentrated in countries where healthcare resources and infrastructure can be limited.
WHO estimates that 10.7 million people fell ill with TB in 2024, while 1.23 million died.
That's why manufacturing preparation matters almost as much as the laboratory result.
If M72/AS01E succeeds, the world won't simply need a scientific paper announcing its efficacy.
It will need millions of doses, affordable production, regulatory approvals, financing, distribution networks, and country-level vaccination programmes.
The Serum Institute agreement is an attempt to address one of those challenges before the trial result arrives.
Whether the gamble pays off remains unknown.
Knowlegic Perspective
It's worth being precise about what has and hasn't actually happened.
A new tuberculosis vaccine has not been approved.
What has happened is more interesting.
An earlier clinical trial produced a genuinely promising result. A much larger Phase 3 trial is now testing whether that result holds up in a broader population. And a major vaccine manufacturer has decided that the potential benefit is significant enough to begin preparing production capacity before the final answer arrives.
That's a very different story from:
"Scientists have cured tuberculosis."
They haven't.
Instead, we're watching something much more realistic and perhaps more important, happen in real time:
Science is moving ahead while the final uncertainty remains.
The century-long gap since BCG also reveals something easy to overlook. Developing a vaccine isn't simply about discovering a promising molecule in a laboratory.
It requires clinical evidence.
Manufacturing.
Regulatory approval.
Funding.
Supply chains.
And eventually, getting doses to the people who need them.
A vaccine that works but arrives years too late isn't enough.
Every tuberculosis vaccine used since 1921 has been BCG.
Now, for the first time in more than a century, a candidate specifically designed to help protect adolescents and adults against pulmonary TB is approaching the final stage of testing.
The earlier evidence is promising.
The Phase 3 answer isn't here yet.
And the manufacturing investment is explicitly conditional on success and regulatory approval.
So the most accurate headline isn't:
"The new TB vaccine has arrived."
It's this:
The world is preparing for the possibility that it finally might.
And after a century of waiting, that's significant enough on its own.
Sources & References
Van Der Meeren, O. et al., "Phase 2b Controlled Trial of M72/AS01E Vaccine to Prevent Tuberculosis," New England Journal of Medicine (2018) — https://www.nejm.org/doi/full/10.1056/NEJMoa1803484
GSK, "GSK candidate vaccine helps prevent active pulmonary tuberculosis in HIV negative adults in phase II study" — https://www.gsk.com/en-gb/media/press-releases/gsk-candidate-vaccine-helps-prevent-active-pulmonary-tuberculosis-in-hiv-negative-adults-in-phase-ii-study/
World Health Organization, "Investing in new TB vaccines: It's time to end the century-long wait!" — https://www.who.int/news/item/16-07-2021-investing-in-new-tb-vaccines
Institut Pasteur, "BCG vaccine: the first tuberculosis vaccination took place a century ago" — https://www.pasteur.fr/en/home/research-journal/news/bcg-vaccine-first-tuberculosis-vaccination-took-place-century-ago
University of Oxford, "Marking 100 years of the tuberculosis BCG vaccine" (2021) — https://www.ox.ac.uk/news/2021-03-24-marking-100-years-tuberculosis-bcg-vaccine
The Gates Medical Research Institute, "Gates Medical Research Institute and the Serum Institute of India Reach Agreement for the Manufacture of M72/AS01E Tuberculosis Vaccine Candidate" (2026) — https://www.gatesmri.org/gates-medical-research-institute-and-the-serum-institute-of-india-reach-agreement/
Serum Institute of India, official press release on the M72/AS01E manufacturing agreement (2026) — https://www.seruminstitute.com/gates-medical-research-institute-and-the-serum-institute-of-india-reach-agreement.php
Enjoyed this?
Get notified when a new Knowlegic story worth knowing is published.
