'Cheap, Old' Vaccine Might Be Able To Reverse Type 1 Diabetes

BOSTON, MA — Researchers at Massachusetts General Hospital say a "cheap, old" tuberculosis vaccine could be used as a long-term solution to improve the lives of people with diabetes by lowering their blood sugar levels to near normal .

Type 1 diabetes, which is typically diagnosed in kids and young adults, is characterized by the pancreas not making insulin or making very little, according to the federal Centers for Disease Control and Prevention. Insulin is a hormone that allows blood sugar to enter the body's cells and be used for energy.

"Without it, blood sugar can’t get into cells and builds up in the bloodstream," the agency says. "High blood sugar is damaging to the body and causes many of the symptoms and complications of diabetes."

Of note, the CDC says no one knows how to prevent type 1 diabetes, but it can be manageable by controlling blood sugar, among other things.

The latest study, published Thursday in npj Vaccines, touches on that aspect.

The bacillus Calmette-Guérin, or BCG, vaccine seems to change the body's metabolism, allowing cells to consume more sugar, the study found.

“This cheap, old vaccine is lowering blood sugar to levels never achieved before,” said Dr. Denise Faustman of Massachusetts General Hospital, according to STAT.

A group of adults with longstanding type 1 diabetes were given two administrations of the BCG vaccine four weeks apart. Three years later, all members of the group showed an improvement in HbA1c to "near normal levels," the hospital said in a release. And that improvement persisted for the following five years.

“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,” Faustman said in the release. “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.”

The latest results are based on data from 282 participants, 52 of whom had type 1 diabetes. The others contributed blood samples for mechanistic studies.

The HbA1c levels of those who received the vaccine dropped by more than 10 percent three years after treatment and more than 18 percent at four years, the researchers found. That reduction was maintained over the next four years, with participants having an average HbA1c level near the threshold for diabetes diagnosis. There were, notably, no reports of severe hypoglycemia, a condition often associated with diabetes treatment where there's not enough sugar in the blood.

Participants in the placebo group and in a comparison group of patients receiving no treatment experienced consistent HbA1c elevations over the same eight-year time period, the researchers found.

Faustman plans to present five-year follow-up results of a separate group of BCG clinical trial participants on Saturday in Orlando.

Mihai Netea, a professor in the Department of Internal Medicine at Radboud University Medical Center in the Netherlands who was not involved in the study, called the results "exciting."

"The clinical effects and the proposed mechanism demonstrated are exciting and add to the emerging consensus that the BCG vaccine can have a lasting and valuable impact on the immune system," he said.

The Boston hospital's trials and others around the globe could lead to "a major shift" in preventing and treating both infections and autoimmunity.

A second phase of the study is underway, where multiple doses of the vaccine are being tested on a large group of participants with longstanding type 1 diabetes.

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