A Study to Evaluate Immunity to Varicella Zoster Virus After Immunization With V212 Vaccine or Zostavax (V212-003)

A study in two parts (Part A and Part B) to evaluate the responsiveness of various biomarkers of immunity to Varicella-Zoster Virus (VZV) following repeated immunizations with heat treated VZV vaccine V212 or with Zostavax™. The enrollment of participants into this study was conducted in 2 parts, Part A and Part B. The first 42 eligible participants were enrolled into Part A of the study. In Part A, the reaction of the VZV skin test at baseline was evaluated at both 48 and 72 hours post administration of the VZV skin test reagent and saline (in opposite arms), with 2 examiners performing the reading at each timepoint; all subsequent skin test readings in Part A were performed at 48 hours post administration. After all skin test reactions were obtained at baseline for the 42 subjects in Part A, an interim analysis was performed (1) to assess the frequency of baseline negative skin tests in order to confirm that the planned sample size (N=120) was adequate for an evaluation of the effect of vaccination on the VZV Skin Test, and (2) to assess the frequency of baseline positive skin tests at 72 hours relative to 48 hours (post administration) in order to determine the preferred time for evaluation of the skin test reaction. The interim analysis from Part A confirmed the study sample size, an additional 78 subjects were enrolled into Part B to achieve the planned sample size (N=120). The study procedures for Part B of the study were identical to those in Part A with the following exceptions: (1) baseline skin test readings were performed only once, at either 48 or 72 hours (post administration) to accommodate the scheduling of clinic visits, and (2) only one examiner was needed for the skin test reading at baseline.