Role of BCG vaccine in protection. If like me you have been v confused why TB and covid have anything in common...read on....

First of all people noticed that people with diabetes type 1 got better blood sugars and HbA1C after a BCG vaccine if treated in the first month of diagnosis. Yeah weird! A RCT if 5-18yo with chronic diabetes type 1 didn’t agree. But then a new study showed multiple doses did

Improve glucose control in type 1 adults with long term diabetes. It also killed off some auto reactive insulin attracted T cells. Some similar reports in MS cerebral lesions.

Seems BCG highly promotes a glycolysis pathway via TNF a etc. We are all familiar with crazy sugar control during infection and sepsis. But since most immune cells

Switch to a glycolytic pathway in inflammation (T cells and neutrophils anyway) glucose metabolism is key part of stress response

We know this from all the lactate. And the cortisol-sugar relationship. And hypoglycaemia in Addison’s. So we kind of knew all this really.

Anyway it seems BCG could have some permanent effects on immunomodulating immune system. Possibly via weird glucose systems OR and this is slightly more complicated so worth reading up

Self reactive T cells are meant to be in a state of anergy or destroyed in development, we know some still exist though as chronic autoimmune disease can be T cell mediated.

TNFa actually kills off activated T cells (but not quiet ones) so possible that some slightly aggravated self reactive T cells are destroyed peri-vaccination and don’t come along to bite you later when you get inflammatory response to something else.

Truth is stranger than fiction! https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6896902/#s3title