The one second answer is “yes”, but there is an over 100-year-old story behind that. BCG, properly called Bacillus Calmette-Guerin is a live attenuated (weakened) form of tuberculosis. The vaccine has been around for 100 years and is routinely given to children in nearly all non-Western countries to prevent TB. Not long after the vaccine was developed in the 1920’s scientists noted a significant decrease in childhood death rates not only from TB but from many unrelated infections. More recent studies in elderly patients showed a marked reduction in all forms of respiratory infections in mature adults receiving BCG as compared to a placebo shot.
These observations have led to a broader scope of research on BCG around the globe. Here in the US, Harvard Medical School is a front runner in this research. As weird as it may seem it turns out that BCG can not only boost good immunity but paradoxically can also calm an overactive immune system that is causing auto-immune disease. The Harvard team found that BCG triggers the immune system to produce TNF-alpha which does two important jobs. TNF-alpha fights all types of bacterial and viral infections but it also helps the body make T-regulatory cells (T-regs) which act as
“referees” to prevent collateral damage during immune responses.
Unlike type II diabetes, which is due to obesity causing insulin resistance with very high insulin levels, Type I diabetes is due to a lack of insulin production by the pancreas because of an auto-immune destruction of the cells that produce insulin. BCG given as type I diabetes is developing can save some of the pancreas cells that produce insulin before they are all destroyed.
Alzheimer’s disease is currently viewed as an auto-immune disease in the brain where chronic inflammation leads to the amyloid plaque (scar tissue) that disrupts nerve connections. A research group in Israel recently reported on a large cohort of people with bladder cancer. Those who received BCG as a treatment for their bladder cancer had a 2.4 percent occurrence of Alzheimer’s years later versus an 8.9 percent occurrence in a group who did not receive BCG.
This observation has sparked ongoing trials of using BCG in treating early Alzheimer’s and also in MS (multiple sclerosis) another auto-immune brain disease. Other ongoing areas of research using BCG include preventing Covid 19 infection, treating eczema and asthma.
The United States and some other Western nations have never adopted the use of BCG as a prevention for TB, opting instead to treat individual cases as they occur. Pending the outcome of these recent research trials, that policy might change.