CompletedPhase 2

Safety and Immunogenicity of Different Formulations of an MF59-Adjuvanted Influenza Vaccine in Older Adults ≥50 Years of Age

United States1,056 participantsStarted 2022-08-25

Plain-language summary

This Phase 2, randomized, observer-blind, dose-confirmation clinical study evaluated different formulations of MF59-Adjuvanted Quadrivalent Subunit Inactivated Influenza Vaccine. Approximately 1000 subjects were randomized into 1 of 4 possible treatment groups with approximately 250 participants per group. Every participant received an influenza vaccine injection on Day 1 and were to be followed up for approximately 6 months following injection. The primary immunogenicity analysis is based on Day 29 serology data.

Who can participate

Age range

50 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion criteria

. Individuals ≥50 years of age on the day of informed consent.
. Individuals who have voluntarily given written consent after the nature of the study has been explained according to local regulatory requirements, prior to study entry.
. Individuals who can comply with study procedures including follow-up .
. Males, females of non-childbearing potential or females of childbearing potential who are using an effective birth control method, at least 30 days prior to informed consent, which they intend to use for at least 2 months after the study vaccination.

Exclusion criteria

. Females of childbearing potential who are pregnant, lactating, or who have not adhered to a specified set of contraceptive methods from at least 30 days prior to informed consent and who do not plan to do so for at least 2 months after the study vaccination.

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Immunogenicity Endpoint: Geometric Mean Titer (GMT): Geometric Mean of Hemagglutination Inhibition (HI) Antibodies at Day 1 and Day 29

Timeframe: Day 1 and Day 29

Immunogenicity Endpoint: Geometric Mean Fold Increase (GMFI) (HI Assay)

Timeframe: Day 1 to Day 29

Immunogenicity Endpoint: Percentages of Subjects With HI Titers ≥1:40 at Day 1 and Day 29

Timeframe: Day 1 and Day 29

Immunogenicity Endpoint: Percentage of Subjects With Seroconversion at Day 29 (HI Assay)

Timeframe: Day 1 to Day 29

Immunogenicity Endpoint: GMT Ratio (HI Assay)

Timeframe: Day 29

Solicited Local or Systemic AEs

Timeframe: Day 1 through Day 7

Severe Solicited Local or Systemic AEs

Timeframe: Day 1 through Day 7

Trial details

NCT IDNCT05501561

SponsorSeqirus

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2023-03-31

Results submitted2026-03-23

View on ClinicalTrials.gov More Influenza, Human trials

Plain-language summary

Who can participate

Age range

50 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion criteria

. Individuals ≥50 years of age on the day of informed consent.
. Individuals who have voluntarily given written consent after the nature of the study has been explained according to local regulatory requirements, prior to study entry.
. Individuals who can comply with study procedures including follow-up .
. Males, females of non-childbearing potential or females of childbearing potential who are using an effective birth control method, at least 30 days prior to informed consent, which they intend to use for at least 2 months after the study vaccination.

Exclusion criteria

. Females of childbearing potential who are pregnant, lactating, or who have not adhered to a specified set of contraceptive methods from at least 30 days prior to informed consent and who do not plan to do so for at least 2 months after the study vaccination.

What they're measuring

Immunogenicity Endpoint: Geometric Mean Titer (GMT): Geometric Mean of Hemagglutination Inhibition (HI) Antibodies at Day 1 and Day 29

Timeframe: Day 1 and Day 29

Immunogenicity Endpoint: Geometric Mean Fold Increase (GMFI) (HI Assay)

Timeframe: Day 1 to Day 29

Immunogenicity Endpoint: Percentages of Subjects With HI Titers ≥1:40 at Day 1 and Day 29

Timeframe: Day 1 and Day 29

Immunogenicity Endpoint: Percentage of Subjects With Seroconversion at Day 29 (HI Assay)

Timeframe: Day 1 to Day 29

Immunogenicity Endpoint: GMT Ratio (HI Assay)

Timeframe: Day 29

Solicited Local or Systemic AEs

Timeframe: Day 1 through Day 7

Severe Solicited Local or Systemic AEs

Timeframe: Day 1 through Day 7