After all of the subjects have completed and assays resulted, the study will be unblinded. The subjects who received placebo will be offered Zostavax vaccine at no cost and will be offered the chance to go into the Follow Up Period described above. The placebo subjects do not have to participate in the Follow Up Period to receive the Zostavax vaccine. The subjects can opt to receive the vaccine or not receive the vaccine or receive the vaccine and give blood on day 1 and again at 6 weeks and also have the option to get the monthly calls for 4 months.