Shingles vaccine is live vaccine i.e. contain a version of the pathogen (Vericella Zoster virus) that has been weakened in the lab so it can�t cause disease. Once injected, your body's immune response recognizes the agent as foreign, destroys it, and remembers it (as an anti-body) and that is why it is usually preferred in healthy individuals. Shingles vaccine is only known to reduce the severity and duration of pain and discomfort associated with shingles. Moreover, you get shingles only when you are stressed out, weakening your immune system.

Live Attenuated vaccine: http://www.niaid.nih.gov/topics/vaccines/understanding/pages/typesvaccines.aspx#live