The Bill & Melinda Gates Foundation announced this week that they were allocating $400 million to advance a TB vaccine candidate, M72/AS01E (M72), through a Phase III clinical trial. Additionally, the Wellcome Fund pledged to provide up to $150 million necessary to complete the study.
If proven effective, the tuberculosis (TB) vaccine candidate will become the first in more than a 100 years to help prevent pulmonary TB, a form of active tuberculosis.
“TB remains one of the world’s deadliest infectious diseases,” says Julia Gillard, chair of the Board of Governors at Wellcome. “The development of an affordable, accessible vaccine for adults and adolescents would be game-changing in turning the tide against TB.”
An estimated 10.6 million people globally fell ill with tuberculosis, and 1.6 million died in 2021. The disease primarily affects people in low- and middle-income countries, and people at highest risk often live in poverty and face undernutrition.
Mycobacterium tuberculosis, a bacteria that causes the disease, can stay dormant in the body for years before progressing into an active form of tuberculosis that shows symptoms. Up to a quarter of the world’s population is thought to have latent disease.
The Phase III clinical trial of M72 will assess its efficacy in preventing the progression from latent TB infection to pulmonary TB. The study will enroll about 26,000 people, including those living with HIV and without TB infection, at more than 50 trial sites in Africa and Southeast Asia.
The M72 vaccine candidate is one of 17 TB vaccine candidates currently in the pipeline. The Phase IIb trial involving 3,575 adults provided 54% protection against active pulmonary TB in people with latent infection — an unprecedented result in decades of TB vaccine research. The vaccine did not raise any evident safety concerns.
British pharmaceutical company GSK is developing the TB vaccine in partnership with Aeras, a non-profit biotech organization, and the International AIDS Vaccine Initiative (IAVI).
The World Health Organization (WHO) estimates that a vaccine with at least 50% efficacy could prevent up to 76 million new TB cases and 8.5 million deaths over 25 years.
Symptoms of pulmonary TB disease may include:
- Cough lasting 3 or more weeks
- Chest pain
- Coughing up blood or sputum (phlegm)
These symptoms can be accompanied by fever, weight loss, night sweats, fatigue, and decreased appetite.
The new vaccine could significantly relieve the global burden of tuberculosis both in terms of saved lives and household costs.