ABOVE: © MESA SCHUMACHER
BCG, or the Bacille Calmette-Guérin vaccine, elicits a multipronged immune response that effectively fends off tuberculosis in children in developing countries, where the disease is still common. But the vaccine’s protection wanes with age, and the pathogen can infect adolescents and adults, causing a lung disease characterized by a persistent, sometimes bloody cough. Researchers aren’t sure which parts of the immune response are most critical for protection to be effective, and are taking varied approaches to improve on BCG with next-generation tuberculosis (TB) vaccines. One leading candidate shown here involves the same microbe as BCG, but with a few genetic tweaks that researchers hope will provide better protection. Another takes an entirely different approach with manipulated antigens from the BCG bacterium. Still other TB vaccines in the pipeline include live and killed whole mycobacteria of various species—including Mycobacterium tuberculosis, which causes tuberculosis—and viral delivery of the ...
