Phase 3 Single Arm, Open Study on vYF in Adults

The purpose of this study is to assess the safety and immunogenicity of vYF in adults aged 18 years and over in Japan. Study details include: * The study duration will be up to approximately 1 month. * One single dose of vYF will be administrated subcutaneously at the 1st visit. * The visit frequency will be Day 01 (Visit 01) and Day 29 (Visit 02). One telephone call (TC) will be planned at Day 15. Number of Participants: A total of 254 participants is expected to be included in the study with the aim to obtain a total of 203 evaluable participants. Study Arms and Duration: Eligible participants will receive, subcutaneously, a single dose of vYF vaccine on Day 1. The duration of each participation will be approximately 1 month for each participant.