In a clinical trial, the new vaccine halved the number of people who developed active TB from latent infections, of 1,623 participants. “The results are extremely encouraging,” says Richard Chaisson, an infectious disease physician and director of the Johns Hopkins Center for Tuberculosis Research. The only currently available tuberculosis vaccine, bacille Calmette-Guérin, or BCG, was developed nearly a century ago in 1921 and isn’t effective for adults. About one quarter of the world’s population, about 1.7 billion people. is estimated to have a latent infection. But around 10 to 15 percent will go on to develop tuberculosis.
The new vaccine is made of two proteins from the bacteria that provoke an immune response in people, plus a substance that enhances that response. Identifying people at higher risk and treating them with antibiotics is a viable strategy. At the same time, focusing on people already infected is a novel approach that could have a key role in tuberculosis control. Tbis a major focus for global health. The United Nations is holding its first ever high-level meeting on the disease in New York on Wednesday. The new vaccine needs to be tested in much larger numbers of people.