This Phase 2, randomized, observer-blind, active controlled clinical study is evaluating the safety and immunogenicity of the investigational MF59-Adjuvanted Quadrivalent Subunit Inactivated Influenza Vaccine.

Approximately 480 subjects are to be randomized into 1 of 4 possible treatment groups (investigational Influenza Vaccine or licensed Quadrivalent Influenza Vaccine comparators) at 120 participants per group.

Every participant will receive an influenza vaccine injection on Day 1 and will be followed up for approximately 6 months following injection. The primary immunogenicity analysis is based on Day 29 serum.