BCG Vaccine Could Permanently Reverse Type 1 Diabetes

Results of a new clinical trial show that the bacillus Calmette-Guerin (BCG) vaccine could permanently reverse advanced type 1 diabetes in mice, as well as help to restore proper immune response to insulin-producing beta cells. The BCG vaccine, which is based on a harmless strain of bacteria related to one that causes tuberculosis (TB) and is also approved in the U.S. to treat bladder cancer, is used in China, Africa and South America to vaccinate against TB, but it is not given to children in the U.S. because TB isn’t common.

According to Denise Faustman, PhD, director of the Massachusetts General Hospital Immunobiology Laboratory that led the clinical trial, the BCG vaccine could induce a permanent gene express that restores regulatory T cells (Tregs) that help to prevent the immune system attack that characterizes type 1 diabetes. “Repeat BCG vaccination appears to permanently turn on signature Treg genes, and the vaccine’s beneficial effect on the host immune response recapitulates decades of human co-evolution with mycobacteria, a relationship that has been lost with modern eating and living habits,” said Dr. Faustman.

Dr. Faustman and her team were the first to document type 1 diabetes reversal in mice, as well as in a subsequent successful Phase I trial among humans, for which long-term data is expected to be published later this year. Currently, a Phase II, 150-person trial is recruiting to assess whether repeat BCG vaccination can improve or even reverse advanced type 1 diabetes in adults. Belgian biotech company Imcyse announced it will begin human trials across Europe of a separate type 1 diabetes vaccine, with results expected in 2018.