Study duration per participant was approximately 28 days including: 1 day of screening and vaccination, a safety follow-up telephone call and an end of study visit approximately at Day 8 and 28 after vaccination, respectively.
Primary Objective:~To demonstrate that QIV-HD induced an immune response (as assessed by hemagglutination inhibition [HAI] geometric mean titers [GMTs] and seroconversion rates) that was superior to responses induced by QIV-SD for the 4 virus strains at 28 days post-vaccination in all participants.~Secondary Objective:~To describe the immune response induced by QIV-HD and QIV-SD by HAI measurement method in all participants.~To describe the safety profile of all participants in each study group.