Century-Old TB Vaccine May Cut Insulin Needs for Diabetics

Imagine if a vaccine created a century ago to fight tuberculosis could also help people manage diabetes better.

New clinical trial results suggest the BCG vaccine, which has protected against tuberculosis for 100 years, may reduce insulin needs and improve blood sugar control in people with type 1 diabetes. The findings were presented at the American Diabetes Association's annual meeting in New Orleans this June.

About 2 million Americans live with type 1 diabetes, an autoimmune disease that destroys the pancreas's insulin-making cells. People with the condition must monitor their blood sugar and inject insulin multiple times daily, carefully calculating every dose to avoid dangerous crashes or long-term damage to their heart, kidneys, eyes, and nerves.

The trials tracked 34 adults with childhood-onset type 1 diabetes who received six doses of the BCG vaccine over five years, compared to 24 who received a placebo. The vaccinated group saw meaningful improvements in their average blood sugar levels and spent up to 183% more time in a healthy blood sugar range than at the trial's start.

Even better, they didn't experience more episodes of dangerously low blood sugar than the unvaccinated group. This matters because balancing insulin doses is one of the most stressful parts of living with type 1 diabetes.

Why This Inspires

For people living with type 1 diabetes, even small improvements in blood sugar control can make a huge difference in daily life. Less insulin needed means fewer injections, fewer calculations with every meal, and less worry about getting the dose wrong.

Dr. Gillian Goddard, an endocrinologist at NYU Langone Health who wasn't involved in the studies, sees potential. "It could be another tool in our arsenal for improving the lives of patients with type 1 diabetes," she told Live Science.

The BCG vaccine is already approved and widely available, which means if larger trials confirm these results, it could reach patients relatively quickly. No new drug development required, just a new use for an old friend.

These are phase 2 trials, so larger studies will be needed to fully understand the benefits. Some researchers remain cautiously optimistic, noting that type 1 diabetes research has had many promising leads that didn't pan out in bigger trials.

Still, for families managing this demanding disease every single day, any new option that could make life a little easier is worth celebrating.