Age, immune issues, stress, taxed immune system, and length of time since reexposure to chicken pox virus can all effect shingles activation. In this case it's probably age with the very real potential of immune issues from vaccine. Chicken pox virus is fucking brilliant. New theories suggest that it lies dormant, and continues to do so longer if the body comes in contact with chicken pox again. Most people were reexposed in their 20s or 30s when their kids got it. However, since kids get a chicken pox vaccine now, less reexposure. So, in turn, this brilliant virus re-emerges as shingles, which can cause chicken pox and allow the virus to spread further. This has led to higher prevalence in younger people. I had a small patch appear, lasted about a week, small and quick because I was young. It felt like every spot was randomly stabbed with a needle every few minutes, I couldn't imagine the pain of a large outbreak, it would be constant stabbing all over your body. Edit. Someone posted a link to info on this. https://poal.co/s/Vax/619624