A Phase 3 interventional study of aQIV or aTIV and QIV or TIV in Influenza, Human, sponsored by Seqirus. Completed at 255 sites in 21 countries. Open to participants aged 65 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-02.
Sponsored by Seqirus · Phase 3, Interventional, and Prevention
This Phase 3 study is a randomized, observer-blind study of MF59-adjuvanted influenza vaccine (aQIV or aTIV) compared with a non-adjuvanted influenza vaccine (QIV or TIV) in adults ≥65 years of age. The aim of the study is to evaluate MF59-adjuvanted influenza vaccine compared with non-adjuvanted influenza vaccine in the prevention of reverse transcription-polymerase chain reaction (RT-PCR)-confirmed influenza A and/or B in subjects ≥65 years of age.
In order to participate in this study, all subjects must meet ALL of the inclusion criteria described.
Exclusion Criteria:
In order to participate in this study, all subjects must not meet any of the exclusion criteria described below:
Abnormal function of the immune system resulting from:
MF59-adjuvanted QIV containing 2 influenza type A strains and 2 influenza type B strains or MF59-adjuvanted TIV containing 2 influenza type A strains and 1 influenza type B strain
Biological: aQIV or aTIV
Non-adjuvanted QIV containing 2 influenza type A strains and 2 influenza type B strains or Non-adjuvanted TIV containing 2 influenza type A strains and 1 influenza type B strain
Biological: QIV or TIV
Participants receive a 0.5-mL intramuscular dose of aQIV or aTIV on Day 1. A 0.5 mL dose of aQIV contains nominally 15 µg of hemagglutinin (HA) of each of the 2 influenza type A strains and each of the 2 influenza B strains (total of 60 µg HA). A 0.5 mL dose of aTIV contains nominally 15 µg of HA of each of the 2 influenza type A strains and of the influenza B strain (total of 45 µg HA). The strain composition of aQIV and aTIV is that recommended by the World Health Organization (WHO) for quadrivalent and trivalent influenza vaccines, respectively, contemporaneous to the timing of the study.
Also known as: Fluad Tetra/Quadrivalent or Fluad
Participants receive a 0.5-mL intramuscular dose of the non-adjuvanted QIV or TIV on Day 1. A 0.5 mL dose of QIV contains nominally 15 μg of HA of each of the 2 influenza type A strains and each of the 2 influenza B strains (total of 60 μg HA). A 0.5 mL dose of TIV contains nominally 15 μg of HA of each of the 2 influenza type A strains and of the influenza B strain (total of 45 μg HA). The strain composition of QIV and TIV is that recommended by the WHO for quadrivalent and trivalent influenza vaccines, respectively, contemporaneous to the timing of the study.
Efficacy Endpoint: First-occurrence of RT-PCR-confirmed influenza, due to any influenza Type A and/or B virus (regardless of antigenic match), using the protocol-defined ILI definition
ILI = influenza-like illness; RT-PCR = reverse transcription-polymerase chain reaction
Time frame: From 14 days after vaccination (ie study day 15) and until the end of influenza season (typically end of May for Northern Hemisphere [NH] influenza season and end of November for Southern Hemisphere [SH] influenza season)
Efficacy Endpoint: First-occurrence of RT-PCR-confirmed influenza, due to any influenza Type A and/or B virus (regardless of antigenic match), using the protocol-defined ILI definition
Time frame: From 14 days after vaccination (ie study day 15) and until the end of influenza season (typically end of May for NH influenza season and end of November for SH influenza season)
Efficacy Endpoint: First-occurrence of culture-confirmed influenza, due to influenza Type A and/or B virus antigenically matched to the vaccine strains selected for the seasonal vaccine, using the protocol-defined ILI definition
Time frame: From 14 days after vaccination (ie study day 15) and until the end of influenza season (typically end of May for NH influenza season and end of November for SH influenza season)
Efficacy Endpoint: First-occurrence of culture-confirmed influenza, due to any influenza Type A and/or B virus (regardless of antigenic match), using the protocol-defined ILI definition
Time frame: From 14 days after vaccination (ie study day 15) and until the end of influenza season (typically end of May for NH influenza season and end of November for SH influenza season)
Efficacy Endpoint: First-occurrence of RT-PCR-confirmed influenza, due to any influenza Type A and/or B virus (regardless of antigenic match), using the modified CDC ILI definition
CDC = Centers for Disease Control and Prevention
Time frame: From 14 days after vaccination (ie study day 15) and until the end of influenza season (typically end of May for NH influenza season and end of November for SH influenza season)
Efficacy Endpoint: First-occurrence of RT-PCR-confirmed influenza, due to any influenza Type A and/or B virus (regardless of antigenic match), using the WHO ILI definition
WHO = World Health Organization
Time frame: From 14 days after vaccination (ie study day 15) and until the end of influenza season (typically end of May for NH influenza season and end of November for SH influenza season)
Efficacy Endpoint: First-occurrence of culture-confirmed influenza, due to influenza Type A and/or B virus antigenically unmatched to the vaccine strains selected for the seasonal vaccine, using the protocol-defined ILI definition
Time frame: From 14 days after vaccination (ie study day 15) and until the end of influenza season (typically end of May for NH influenza season and end of November for SH influenza season)
Immunogenicity Endpoint: Pre- and post-vaccination hemagglutination inhibition (HI) geometric mean titers (GMTs) for the A/H1N1, A/H3N2, B/Yamagata, and B/Victoria vaccine strains
Time frame: Day 1 and Day 22
Immunogenicity Endpoint: Geometric mean fold increase (GMFI, Day 22/Day1) for the A/H1N1, A/H3N2, B/Yamagata, and B/Victoria vaccine strains
Time frame: Day 1 and Day 22
Immunogenicity Endpoint: Percentage of subjects achieving seroconversion for the A/H1N1, A/H3N2, B/Yamagata, and B/Victoria vaccine strains
Seroconversion is defined as the percentage of subjects with either a pre-vaccination titer \<1:10 and a post-vaccination titer ≥1:40 or a pre-vaccination titer ≥1:10 and a ≥4-fold increase in post-vaccination titer.
Time frame: Day 1 and Day 22
Immunogenicity Endpoint: Percentage of subjects with HI titer ≥1:40 for the A/H1N1, A/H3N2, B/Yamagata, and B/Victoria vaccine strains
Time frame: Day 1 and Day 22
Safety Endpoint: All adverse events (AEs) reported within 30 minutes after vaccination
Time frame: Day 1
Safety Endpoint: Serious adverse events (SAEs) reported during the entire study period
Time frame: Day 1 to Day 181 or the end of the influenza season, whichever is longer
Safety Endpoint: Adverse events of special interest (AESIs) reported during the entire study period
Time frame: Day 1 to Day 181 or the end of the influenza season, whichever is longer
Safety Endpoint: AEs leading to premature withdrawal from the study during the entire study period
Time frame: Day 1 to Day 181 or the end of the influenza season, whichever is longer
Showing the first 100 of 255 sites across 21 countries.
Plan to share: Yes — Seqirus will consider on a case-by-case basis requests to share Individual Patient Data (IPD) with external bona-fide, qualified scientific and medical researchers. For information on the process and requirements for submitting a voluntary data sharing request for IPD, please contact Seqirus at seqirus.clinicaltrials@seqirus.com.
Supporting information: Study protocol, Sap
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This study is completed, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.
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