Comparison of a Live Herpes Zoster Vaccine and a Recombinant Vaccine in 50-59 and 70-85 Year Olds

160 people from the Denver area will participate. Duration is up to 5 years with 10-12 visits in that period. Subjects are randomized into one of 4 arms to receive either Zostavax or HZ/su. In this single blind study all subjects receive 2 injections: one at the first visit (Day 0) and the second at Day 60. HZ/su subjects will receive vaccine at both visits; Zostavax subjects will receive vaccine at the first visit and a placebo at the Day 60 visit. Blood is collected from all subjects at most visits. Some subjects spit into a tube for saliva collection. A urine sample is collected prior to vaccination if subject is a woman of childbearing potential. Subjects are asked to complete a diary to record any reactions in the 30 days after each injection. The Day 90 visit is the last one until the annual visits for blood draws begin at Day 365. Some subjects are also seen at Year 2 and Year 4; all subjects are seen at Year 5 for blood draw.