Designing self-destructing bacteria to make effective tuberculosis vaccines

Working toward more effective tuberculosis (TB) vaccines, researchers at Weill Cornell Medicine have developed two strains of mycobacteria with “kill switches” that can be triggered to stop the bacteria after they activate an immune response. Two preclinical studies, published, Jan. 10 in Nature Microbiology, tackle the challenge of engineering bacteria that are safe for use in controlled human infection trials or as better vaccines. While TB is under control in most developed countries, the disease still kills over a million people a year worldwide. Spreading easily through the air, Mycobacterium tuberculosis can establish a chronic infection in human lungs, which can turn into a deadly respiratory disease. A safe vaccine called BCG, consisting of a weakened strain of the closely related Mycobacterium bovis, has been available for over a century but has limited efficacy. “BCG protects children from tuberculosis meningitis, but it doesn’t effectively protect adults from pulmonary tuberculosis, which is why...