the thing with shingles is once you have it it can stay dormant for many years but its still there. then the day comes when you do the thing that ticks it off ... for me its the sun, i am fine if i sunbath in my home area but if i go to where the sun is stronger and do not use a sunscreen on my neck .... had my 1st encounter in my late thirties, two more times since then and i am fifty eight now and it has been at least ten years since the last time.
i did not know that the shot could help you if you had shingles already,usually a vaccine is to prevent you from getting something you never had ... will have to look into this.
Stress seems to be my trigger.