An experimental vaccine proved 54% effective at preventing latent tuberculosis infection from turning into active disease. The results were shared on Tuesday, following a study published in the New England Journal of Medicine, which shared results from a three-year study of adults in Africa.
Deaths related to TB have reduced, from 1.6 million in 2017 to 1.5 million in 2018, according to the World Health Organization (WHO). However, it remains one of the top 10 causes of deaths worldwide.
The experimental vaccine was tested in more than 3,500 adults infected with tuberculosis (TB) in three countries where TB is endemic — Kenya, South Africa, and Zambia. It did not have evident safety concerns.
The study stated: “An effective tuberculosis vaccine for … persons [infected with active TB] could have a marked effect on tuberculosis control, including drug-resistant tuberculosis, through interruption of transmission.”
Currently, the only licensed tuberculosis vaccine (bacille Calmette–Guérin, or BCG), does not offer substantial protection against pulmonary adults infected by the active TB disease. It is given to children, who have a higher risk of catching TB. Researchers have been seeking a vaccine that works in adults, and this may be it.
Dr. Paula Fujiwara, scientific director of the International Union Against Tuberculosis and Lung Disease, told the Associated Press that plans are underway for another, definitive study, which will take at least several more years.
After early results from the study were announced last year, the WHO called the vaccine a major breakthrough. This experimental vaccine is part of numerous innovations meant to tackle the disease, including a new test that could identify TB in patients in less than one hour.
Tuberculosis is caused by bacteria spread through the air when a person with the disease coughs or speaks. According to the Centers for Disease Control, the bacteria most commonly grows in the lungs and symptoms include a bad and persistent cough, coughing up blood or mucus, and chest pain. It is curable and preventable, but can also be deadly.
The disease disproportionately impacts low-income and marginalized people. Countries with the highest infection rates include Bangladesh, China, India, Indonesia, Nigeria, Pakistan, the Philippines, and South Africa.
Although more people with TB are receiving treatment than ever before (7 million people receiving treatment in 2018, up from 6.4 million in 2017), the WHO estimates that 3 million people living with tuberculosis do not have access to the care they need.
In addition, to being the top infectious killer in the world, TB is the leading killer of people with HIV, causing one in three AIDS-related deaths, according to UNAIDS.