TB vaccine from the 1920s shows promise in diabetes trial

The Bacillus Calmette-Guérin (BCG) vaccine, originally developed in the 1920s to combat tuberculosis, has demonstrated potential in a new clinical trial for treating type 1 diabetes. Published in Nature on June 9, 2026, the study details how the vaccine reduced insulin requirements for participants with type 1 diabetes and an additional autoimmune condition. This finding builds upon earlier research suggesting BCG's ability to reset the immune system, potentially offering a novel therapeutic avenue for autoimmune diseases. The trial involved a cohort of patients who received the BCG vaccine, and the results indicated a statistically significant decrease in their daily insulin dosage compared to a control group. Researchers are optimistic about further investigation into BCG's immunomodulatory effects, which could lead to new treatment strategies beyond its established role in infectious disease prevention. The study highlights the repurposing of existing vaccines for new indications, a strategy that can accelerate the development of treatments by leveraging established safety profiles and manufacturing processes. Further trials are planned to confirm these promising results and explore the long-term efficacy of BCG in managing type 1 diabetes.