Flublok or Fluzone With Advax-CpG55.2 or AF03

This is a Phase I, randomized, double blinded, clinical trial in up to 240 males and non-pregnant females, 18-45 years of age, inclusive, who are in good health and meet all eligibility criteria. This clinical trial is designed to assess the safety, reactogenicity and immunogenicity of either the 2018/2019 seasonal Fluzone or Flublok Quadrivalent Influenza Vaccine (QIV) manufactured by Sanofi Pasteur (SP) given without adjuvant or with one of two adjuvant formulations, AF03 or Advax-CpG55.2. Subjects will be stratified by prior receipt of licensed, seasonal influenza vaccine (defined as receipt of at least one of the 2017/2018 and/or 2018/2019 influenza vaccines) and will be randomly assigned to 1 of 6 treatment arms to receive a single dose of one of the two seasonal 2018/2019 QIV vaccine formulations with or without one of the two adjuvants (Day 1). On approximately Day 90, each subject will receive a single dose of the seasonal 2019/2020 QIV. Groups 1, 2 and 3 will receive 2019/2020 Fluzone QIV and Groups 4, 5 and 6 will receive 2019/2020 Flublok QIV. Eight Vaccine and Treatment Evaluation Unit (VTEU) sites will be included in the study. Study duration is approximately 18 months, and subject participation duration is 12 months. The primary objectives of this study are: 1) to assess the safety and reactogenicity of 2018/2019 Fluzone and Flublok with and without AF03 or Advax-CpG55.2 adjuvant; 2) to assess the serum hemagglutination inhibition (HAI) antibody responses against 2018/2019 QIV strains from baseline (Day 1) to approximately Day 29 after receipt of 2018/2019 Fluzone and Flublok with and without AF03 or Advax-CpG55.2 adjuvant; 3) to assess the serum neuraminidase inhibition antibody (NAI) responses by enzyme-linked lectin assay (ELLA) against NA antigens in the 2018/2019 QIV from baseline (Day 1) to approximately Day 29 after receipt of 2018/2019 Fluzone and Flublok with and without AF03 or Advax-CpG55.2 adjuvant; 4) to assess the influenza neutralizing (Neut) antibody titer responses against 2018/2019 QIV strains from baseline (Day 1) to approximately Day 29 after receipt of 2018/2019 Fluzone and Flublok with and without AF03 or Advax- CpG55.2 adjuvant. The secondary objectives of this study are: 1) to assess protocol specified adverse events of special interest (AESI), medically-attended adverse events (MAAEs), including new-onset chronic medical conditions (NOCMCs) and potentially immune-mediated medical conditions (PIMMCs) that occur after receipt of study product; 2) to assess the HAI, Neut and NAI ELLA responses to the 2019/2020 QIV strains prior to (Day 1) and approximately 28 days after vaccination with the 2019/2020 QIV in all study groups; 3) to assess the HAI antibody responses against heterologous influenza A/H1 and H3 strains from baseline (Day 1) to approximately Days 8, 29, 57, 90 and 118 after receipt of 2018/2019 Fluzone or Flublok with and without AF03 or Advax-CpG55.2 adjuvant; 4) to assess NAI ELLA responses against heterologous N1 and N2 NA antigens from baseline (Day 1) to approximately Days 8, 29, 57, 90 and 118 after administration of 2018/2019 Fluzone with and without AF03 or Advax-CpG55.2 adjuvant; 5) to assess the influenza neutralizing (Neut) antibody titer responses against heterologous influenza A/H1 and H3 strains from baseline (Day 1) to approximately Days 8, 29, 57, 90 and 118 after administration of 2018/2019 Fluzone and Flublok with and without AF03 or Advax-CpG55.2 adjuvant; 6) to assess the longitudinal kinetics and durability of the HAI, NAI, and Neut responses against the 2018/2019 QIV strains on approximately Days 8, 57, 90 and 118 following receipt of the 2018/2019 Fluzone and Flublok with and without AF03 or Advax-CpG55.2 adjuvant.