Immunogenicity and Safety of a 1-dose Regimen of a Zoster Vaccine Versus Different 2-dose Regimens in Participants ≥ 70 Years of Age. (V211-043)

Primary objective: Immunogenicity To demonstrate that a second dose of ZOSTAVAX® elicits higher varicella-zoster virus (VZV) antibody titres than a first dose of ZOSTAVAX® whether given as a 0-1 month schedule or as a 0-3 month schedule in subjects ≥70 years of age as measured at 4 weeks post-vaccination Secondary objectives Immunogenicity * To summarise the VZV antibody titres at 4 weeks post-vaccination after a 1-dose regimen and 4 weeks post-vaccination after each dose of each 2-doses regimen of ZOSTAVAX®. * To compare the VZV antibody titres at 12 months after completion of a 1-dose regimen with the VZV antibody titres at 12 months after completion of each 2-doses regimen of ZOSTAVAX® * To summarise the VZV antibody titres at 24 and 36 months after completion of a 1-dose regimen and at 24 and 36 months after completion of each 2-doses regimen of ZOSTAVAX®