One of the world's oldest vaccines now has a new use. Bacillus Calmette-Guerin, or BCG, is an 80-year-old vaccine designed to treat tuberculosis. Bit it has now been found effective in treating long-term type 1 diabetes, which is on the rise worldwide.
BCG has long been administered to children in developing countries to guard against tuberculosis.
But in a recent clinical trial, researchers at Harvard Medical School found the vaccine was also able to increase insulin production in patients with type 1 diabetes.
Dr. Denise Faustman, the lead researcher, says the team was able to cure type 1 diabetes in mice. And, speaking via Skype, she said in a small clinical trial, the results in humans were also promising.
"What we saw was that even with two very tiny doses of vaccine, four weeks apart, we could start to see the killing of the bad immune cells and to our astonishment the pancreas started making small amounts of insulin again," said Faustman.
Type 1 diabetes destroys insulin-producing cells. People who have the disease must constantly monitor and manage their blood glucose level by inecting insulin.
Faustman says the BCG vaccine worked in these patients by triggering the production of a hormone called "Tumor Necrosis Factor" or "TNF."
"It's been known for 20 years that if anybody receives this vaccine their body makes a hormone called TNF and it is really TNF that we want. But TNF is not a drug so we are using this cheap surrogate to try to induce TNF in people with long-term diabetes," she explained.
The BCG vaccine often produces a positive result in skin tests used to diagnose tuberculosis.
But Dr. Faustman says if BCG is not found to be effective in treating type 1 diabetes - at least those who receive the vaccine will be protected for some time against TB.
She expects that identifying the correct dose of BCG will be the major challenge in producing a sustained result for type 1 diabetes patients.