Influenza Vaccine Immunogenicity in Repeatedly Vaccinated Older Adults

NCT07838298 · tracked via the Priya Life Science South Korea tracker

Sponsor

Korea University Guro Hospital

Phase

Phase 4

Started

2026-09-21

Last updated

2026-09-24

Condition(s) studied

Influenza VaccinationOlder Adults (65 Years and Older)ImmunosenescenceImmunogenicityRepeated Vaccination

Investigational drug(s) / intervention(s)

Standard dose influenza vaccineMF59 adjuvanted influenza vaccineHigh dose influenza vaccine →

Standard dose influenza vaccine: A single intramuscular dose of standard dose influenza vaccine administered according to the approved prescribing information.

MF59 adjuvanted influenza vaccine: A single intramuscular dose of MF59 adjuvanted influenza vaccine administered according to the approved prescribing information.

High dose influenza vaccine: A single intramuscular dose of high dose influenza vaccine administered according to the approved prescribing information.

Study summary

The goal of this clinical trial is to compare immune responses to different influenza vaccine formulations in older adults and to understand how immune aging and repeated annual influenza vaccination affect these responses.

The main questions it aims to answer are:

* Do standard dose, MF59 adjuvanted, and high dose influenza vaccines produce different immune responses in adults aged 65 years or older?
* How does immune aging affect responses to different influenza vaccine formulations?
* How do immune responses change with repeated annual influenza vaccination, and do these changes differ among vaccine formulations?

Researchers will compare older adults who receive a standard dose, MF59 adjuvanted, or high dose influenza vaccine. Younger adults aged 19-49 years who receive a standard dose influenza vaccine will also be included as a reference group to help evaluate age related differences in immune responses.

Participants will:

* Receive an influenza vaccine.
* Provide blood samples before and after vaccination to measure antibody and other immune responses.
* Some participants will provide additional blood or nasal samples for more detailed evaluation of immune responses.

Eligibility

Sex

ALL

Min age

19 Years

Max age

—

Healthy volunteers

Accepted

Inclusion Criteria: * Older adult group: aged 65 years or older * Younger reference group: aged 19 to 49 years * Able to receive influenza vaccination and complete the scheduled follow up Exclusion Criteria: * Receipt of an influenza vaccine or any other vaccine within 4 weeks prior to enrollment * Immunocompromised status, including ongoing chemotherapy or immunosuppressive therapy, high dose corticosteroid therapy, history of solid organ or hematopoietic stem cell transplantation, active malignancy, HIV infection, or other clinically significant immunocompromising conditions * Moderate or severe acute infection * History of allergic reaction to an influenza vaccine or any of its components, or any other condition that precludes influenza vaccination * Inability, as determined by the investigator, to understand the purpose and procedures of the study and provide voluntary informed consent

Primary outcome measure(s)

Geometric mean titers of hemagglutination inhibition antibodies at 1 month after vaccination — 1 month after vaccination, annually for up to 3 years
Geometric mean titers (GMTs) of hemagglutination inhibition antibodies against each influenza vaccine strain will be assessed at 1 month after vaccination.
Geometric mean fold rise in hemagglutination inhibition antibody titers at 1 month after vaccination — Baseline to 1 month after vaccination, annually for up to 3 years
Geometric mean fold rises (GMFRs) in hemagglutination inhibition antibody titers from baseline to 1 month after vaccination will be assessed for each influenza vaccine strain.

Trial sites (1)

Facility	City	Region	Status
Korea University Guro Hospital	Seoul	South Korea	Recruiting

More Korea University Guro Hospital trials in South Korea

Impact of CES1 Genotype on Remimazolam Recruiting

Quantitative Chest CT and Multi-Omics to Distinguish Asthma From COPD and Predict Treatment Response Recruiting

Two-channel IV-PCA With Dexmedetomidine Recruiting

OCT-Guided Stent Optimization for Short-Duration Dual Antiplatelet Therapy in Stable Angina Recruiting

Evaluation of an Opioid Stewardship Program in Non-Cancer Patients Recruiting

Other trials for the same condition

Real-world Immunogenicity of Anti-IL5/5a Antibody Active, not recruiting

Influenza Vaccination Strategy for Patients With Hematologic Malignancy Recruiting

Official registry record

This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.

View NCT07838298 on ClinicalTrials.gov ↗ ← All trials in South Korea