A Single Ascending Dose Study in Adults (Stage 1) and Single Ascending Dose-Finding Study (Stage 2) in Elderly Subjects With ASP3772, A Pneumococcal Vaccine

The purpose of the study is to evaluate the safety, tolerability, and immunogenicity of 3 different dose levels of ASP3772 in comparison to the active comparator Prevnar 13® (PCV13) in adults 18 to 64 years of age in Stage 1. Stage 2 will evaluate the safety, tolerability, and immunogenicity of 3 different dose levels of ASP3772 in comparison to the active comparator PCV13 in elderly 65 to 85 years of age. In addition, Stage 2 will evaluate the immunogenicity of 3 different dose levels of ASP3772 relative to the response seen following administration of Pneumovax® 23 (PPSV23) for the serotypes not included in PCV13.