I got shingles within a week or two of quitting vaping more or less cold turkey. I'm 39, very fit, overall healthy, etc -- except for the nasty and long-lived nicotine addiction. I do believe there is a strong connection to quitting and getting shingles -- not that quitting predicts or necesitates getting shingles. But it's not a coincidence when they happen together. Anyway, an odd fact that you will find is that current smokers are actually less likely than the average person to get shingles. Something about the way smoking manipulates the t-cells, is the theory there. Obviously it's not a reason to smoke or delay quitting. It's just an interesting phenomenon born out of our very complex immune system.