BCG can reverse Type 1 diabetes to almost undetectable levels, eight-year study shows

An eight-year study has shown the Bacillus Calamine Guerin (BCG) vaccine against tuberculosis can reverse Type 1 diabetes to almost undetectable levels.

United States (US) researchers found that just one jab, followed by a booster four weeks later, brought down average blood sugar levels to near normal within three years, and the effect lasted for the following five years. According to the report published in The Telegraph UK, experts hailed the results as “very exciting” and said such a treatment would be a “major advance” in the treatment of Type 1 diabetes.

Type 1 diabetes is an autoimmune disease where the body attacks cells in the pancreas, which produce insulin. Insulin is needed to move sugar from the blood to cells where it is used as energy and without regular top-up injections, patients can fall into a lethal coma.

But the new study suggests that just two injections of BCG could virtually cure the condition for many years at a time.

“This is clinical validation of the potential to stably lower blood sugars to near normal levels with a safe vaccine, even in patients with longstanding disease,” said Dr. Denise Faustman who led the trial at Massachusetts General Hospital.

“In addition to the clinical outcomes, we now have a clear understanding of the mechanisms through which limited BCG vaccine doses can make permanent, beneficial changes to the immune system and lower blood sugars in type 1 diabetes.”

Used for almost a century to prevent tuberculosis, the BCG vaccine helps boost and regulate the immune system. The team also discovered that the jab speeds up the rate by which cells convert glucose into energy and tests on mice show that it could also be beneficial against Type 2 diabetes.

The new study involved 52 people with Type 1 diabetes. After three years of treatment average blood sugar levels had dropped by 10 per cent and by 18 per cent after four years. Treated participants had an average blood glucose score of 6.65, close to the 6.5 considered the threshold for diabetes diagnosis.

In comparison, the blood sugar of those in the placebo group continued to rise over the trial period.

Commenting on the research, Prof Helen McShane, Professor of Vaccinology, at the University of Oxford, said: “The finding that two doses of BCG, a safe vaccine that is almost 100 years old, can significantly improve the control of blood glucose in patients with established type-1 diabetes, is very exciting.

“This well conducted study provides data to support a plausible immunological mechanism for this durable effect, and adds to an increasing body of knowledge on the effects of BCG on autoimmune diseases.

“The effects observed here, which intriguingly increase over time, may provide a highly cost-effective way to reduce the significant morbidity and mortality associated with this disease.”

Prof Andrew Hattersley FRS, Professor of Molecular Medicine, University of Exeter Medical School, said if it was proven to be effective it would be a ‘major advance,’ but warned it had only been proven in a few people.

“This is far too small a number of people studied to suggest this should be considered a potential treatment for people living with Type 1 diabetes,” he said.

Prof Daniel Davis, Professor of Immunology, University of Manchester, said: “Relatively small numbers of patients have been studied here but the research does indicate a fascinating and important way in which the power of our immune system could be tweaked by exposure to BCG vaccination.

“More research should, and is, being done to establish definitely whether or not this could help patients with Type I diabetes, and maybe even other autoimmune diseases.”