Vaping causes inflammation, nicotine suppresses the immune system (which is probably pretty bad news for fighting any other diseases), and nicotine cessation has been linked with an increase in development of autoimmune disorders in the 12-24 month period after quitting.
I had elevated white blood cells counts and I developed an autoimmune condition a few months after quitting vaping. I had good health record leading up to it and no family history of any autoimmune disorders. White blood cells eventually normalized but autoimmune is forever, although it's under control and I'm lucky that it was caught early.
In the final ~4 years of vaping I didn't use any flavorings either, just 70/30 mix of VG/PG and nicotine.
It's not terrible as far as vices go, much less harmful than the alternatives, but it's definitely not as harmless as I thought going in. I wish I hadn't started and went for the ADHD assessment right away instead of subconsciously self-medicating with nicotine.
> linked with an increase in development of autoimmune disorders in the 12-24 month period after quitting
No shit, I had no idea.
That explains a lot. I quit smoking (well, the first time I tried to quit) when I was 19 (2 years smoking). 3 months later I was in the hospital with sclerosing mesenteritis, a rare disorder for an older person but baffling and way out of left-field for a 19 year old with no prior history autoimmune issues. We only got a diagnosis after full exploratory surgery that earned me a six inch incision scar on my stomach.
Don't start smoking, kids.
Word. I quit nicotine and it triggered auto immune response, I got celiac disease. Never touched it ever again and I had to stop eating like a normal person. No more fast food for the rest of my life.