A promising vaccine that has the potential to reverse the symptoms of type I diabetes—an autoimmune disease often diagnosed in childhood—is heading on to a phase II trial, which will test the vaccine on humans with the chronic disease.

The vaccine, called bacillus Calmette-Guérin (BCG) has succeed in reversing type 1 diabetes in a trial among mice and in a phase I trial in 103 humans. The new trial, which the researchers announced on Sunday at the Scientific Sessions of the American Diabetes Association, will last for five years and will test the effect of the vaccine on people with type 1 diabetes among adults between ages 18 to 60. The vaccine may be able to improve the disease in people who have small but detectable levels of insulin coming from their pancreas. Lead researcher Dr. Denise Faustman, director of immunobiology at Massachusetts General Hospital (MGH), estimates that about one…