BCG Vaccination May Defeat Type 1 Diabetes

At the recent 2021 Annual Scientific Sessions of the American Diabetes Association, researchers from Massachusetts General Hospital (MGH) presented positive updates on their trials of the bacillus Calmette-Guérin (BCG) vaccine to safely and significantly lower blood sugars.

Currently, 143 type 1 diabetics have received at least two doses of the BCG vaccine, including 25 patients enrolled in a recently launched trial of adults who had pediatric onset. Pending FDA approval, MGH aims to launch a multi-center pediatric trial later this year.

In type 1 diabetes, an autoimmune disease that currently has no cure, says the U.S. CDC. T cells attack the pancreas and destroy its ability to create insulin, a hormone vital in allowing glucose to enter cells to produce energy.

In prior work, Denise Faustman, M.D., Ph.D., director of the MGH Immunobiology Laboratory, and colleagues have found that BCG boosts a substance called TNF, eliminating the harmful T cells and aids the development of beneficial ones called regulatory T cells, or Tregs.

Key findings include a new understanding of how the response to BCG vaccination differs depending on a patient's age of onset and additional support for the role of BCG vaccination to alter glucose transport and change Tregs.

"More data from randomized double-blinded clinical trials will be reported as we move towards additional readout of the Phase II trial," stated Dr. Faustman, principal investigator of BCG clinical trials at MGH, in a press release issued on June 25, 2021.

"We have continued evidence of BCG's ability to reset and restore the immune system."

In June 2018, MGH announced results of the follow-up of Phase I trial of BCG-treated long-term diabetic participants, showing lasting clinically and statistically significant drops in HbA1c values that persisted with eight years of follow-up.

"BCG is an old vaccine, but it seems to be presenting new gifts," says Nigel Curtis, M.D., Ph.D., of the Murdoch Children's Research Institute in Melbourne, Australia. He directs global clinical trials on the beneficial and off-target effects of the BCG vaccine but was not involved in the current study.

Merck's Bacille Calmette-Guerin vaccine is an attenuated, live culture preparation of the BCG strain of Mycobacterium Bovis. The TICE® strain used in the Merck BCG vaccine preparation was developed at the University of Illinois from a Pasteur Institute strain. The WHO recommends neonatal BCG vaccination in countries or settings with a high incidence of tuberculosis.