Immunogenicity and Safety Trial of Quadrivalent Influenza Vaccine Administered by Intradermal Route in Adult Subjects Aged 18 Through 64 Years

The aim of the study is to demonstrate safety and immunogenicity of the quadrivalent
influenza intradermal (QIV-ID) vaccine compared to the trivalent influenza vaccine (TIV)
containing the B strain from the primary (Yamagata) lineage (TIV-ID1) and the trivalent
influenza vaccine containing B strain from the alternate (Victoria) lineage (TIV-ID2)
vaccines in producing protection against four strains of influenza virus.

Primary Objective:

- To demonstrate that QIV-ID induces an immune response (as assessed by hemagglutination
inhibition (HAI) geometric mean titers (GMTs) and seroconversion rates) that is
non-inferior to responses induced by TIV-ID1 and TIV-ID2 for the 4 virus strains at 28
days post-vaccination.

Secondary Objectives:

- To demonstrate that each B strain in QIV-ID induces an immune response (as assessed by
HAI GMTs and seroconversion rates) that is superior to the response induced by the
TIV-ID that does not contain the corresponding B strain.

- To describe the rate of post-vaccination seroprotection induced by QIV-ID and TIV-ID.

- To describe post-vaccination immunogenicity stratified by age (18-49 years and 50-64
years), race, ethnicity, gender, previous vaccination status, and baseline
seropositivity status.

- To describe the safety profile for subjects who receive QIV-ID and TIV-ID.

Observational Objectives:

- To demonstrate non-inferiority of QIV-ID compared to TIV-ID in terms of all Grade 2 or
Grade 3 solicited systemic reactions combined

- To demonstrate non-inferiority of QIV-ID compared to TIV-ID in terms of all Grade 3
solicited injection site reactions combined.