Shingles, or herpes zoster, as it is called by doctors, is an interesting disease. There is a bit of truth in both answers that you propose in your question. First, most of us "catch" the virus that causes shingles when we are young. It is best known as "chicken pox." While the acute illness
eventually goes away, the virus itself relaxes in our body for decades, waiting for a chance to break out again. It lives in the nerves themselves, which explains the pattern of the itch and rash when it does come back (which is called by doctors a "dermatomal distribution"). While it is there dormant, your body is able to suppress it due to the normally healthy immune system. When something comes along that makes the immune system less effective, the virus has a chance to express itself again. Stress, other illnesses, and chronic steroid use can all pre-dispose people to developing manifestations of the virus. There is a shot that has been FDA approved to prevent shingles, but it is only approved in those over the age of 65. Please speak with your doctor
about your questions, and see if the shot may be right for you.