You gotta weigh everything, I understand. It can be devastating, it was for my dad. Look up some of the pics and stories of bad cases of shingles, it can be a disaster.
In most case we don't know why.
But let me please warn you, that if you suspect you have shingles, see your doctor right away.
The anti-viral meds are really only effective if you catch the disease within 72 hours. And if you're over 50 you can get post herpetic neuralgia, where the shingles goes away, but the pain stays forever.
You do NOT want that.
In a lot of cases, people feel a tingling or stinging at the site before the blisters/rash appears.
And unless you are REALLY immunocompromised its only on one side of the body.