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 (part of CSL Limited) · 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.
2,356 studies on the registry are indexed under Influenza, Human; 184 are open to participants now.
This study's enrollment of 38,769 is above the median of 227 across 1,957 interventional studies indexed under Influenza, Human.
Browse Influenza, Human studies →Seqirus is the lead sponsor of 53 studies on the registry; none are open to participants now.
Of its 15 completed or terminated interventional studies of FDA-regulated products, 10 (67%) have results posted.
First submitted after Seqirus became part of CSL Limited.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
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:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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. Choose a country and city above to see the rest.
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, Statistical analysis plan
Time frame: Requests for IPD will generally be considered once review by major regulatory authorities (ie FDA, EMA) is complete and the primary publication is available.
Access criteria: Proposed research should seek to answer a previously unanswered important medical or scientific question. Applicable country specific privacy and other laws and regulations will be considered and may prevent sharing of IPD. If the request is approved and the researcher has executed an appropriate data sharing agreement, IPD that has been appropriately anonymized will be available.
No publications or documents are linked to this record.
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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