Influenza VaccinationPhase 4NCT07838298
Influenza Vaccine Immunogenicity in Repeatedly Vaccinated Older Adults
A Phase 4 study testing Standard dose influenza vaccine, MF59 adjuvanted influenza vaccine and High dose influenza vaccine in people with Influenza Vaccination and Older Adults (65 Years and Older), run by Korea University Guro Hospital at 1 site in South Korea.
Trial 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. Read more about this study
- Who is it for?
- Ages 19 years and olderHealthy volunteers can take part
- Conditions the study is for
- Influenza Vaccination, Older Adults (65 Years and Older), Immunosenescence
- What is being tested?
- Standard dose influenza vaccine, MF59 adjuvanted influenza vaccine and High dose influenza vaccine
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 180 participants
- Where
- 1 siteSouth Korea
- Study dates
- 21 Sep 2026to Dec 2028
- Phase
- Phase 4
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 19 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 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
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
South Korea1 site, 1 recruiting
- Recruiting
Korea University Guro Hospital
Seoul
Min Joo Choi, MD, PhD, 82-2-2626-3053, cowgow9696@gmail.com
About this study
Official title: Immunogenicity of Different Influenza Vaccine Strategies in Older Adults in a Repeated Vaccination Setting
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:
Read more
- 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.
- Conditions
- Influenza Vaccination, Older Adults (65 Years and Older), Immunosenescence, Immunogenicity, Repeated Vaccination
- Being tested
- Standard dose influenza vaccine, MF59 adjuvanted influenza vaccine, High dose influenza vaccine
- Medical subject headings
- Influenza, Human
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Standard dose influenza vaccineBiological
A single intramuscular dose of standard dose influenza vaccine administered according to the approved prescribing information.
MF59 adjuvanted influenza vaccineBiological
A single intramuscular dose of MF59 adjuvanted influenza vaccine administered according to the approved prescribing information.
High dose influenza vaccineBiological
A single intramuscular dose of high dose influenza vaccine administered according to the approved prescribing information.
| Study group | Role | What they receive |
|---|---|---|
| older adults- standard dose influenza vaccine | Active comparator | Not described Receives: Biological: Standard dose influenza vaccine |
| older adults- adjuvanted influenza vaccine | Experimental | Not described Receives: Biological: MF59 adjuvanted influenza vaccine |
| older adults- high dose influenza vaccine | Experimental | Not described Receives: Biological: High dose influenza vaccine |
| younger adults- standard dose influenza vaccine | Other | Younger adults aged 19-49 years who receive a standard dose influenza vaccine and serve as a reference group for evaluating age related differences in immune responses Receives: Biological: Standard dose influenza vaccine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Geometric mean titers of hemagglutination inhibition antibodies at 1 month after vaccination
Geometric mean titers (GMTs) of hemagglutination inhibition antibodies against each influenza vaccine strain will be assessed at 1 month after vaccination.
Measured: 1 month after vaccination, annually for up to 3 years
Geometric mean fold rise in hemagglutination inhibition antibody titers at 1 month after vaccination
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.
Measured: Baseline to 1 month after vaccination, annually for up to 3 years
Secondary outcomes (4)
Seroconversion rate following influenza vaccination
The proportion of participants achieving a prespecified serologic response, defined as a fourfold or greater increase in hemagglutination inhibition antibody titer from baseline, will be assessed for each vaccine strain.
Measured: Baseline and 1 month after vaccination, annually for up to 3 years
Frequency of influenza specific B cells following vaccination
The frequency of influenza specific B cells will be assessed at baseline, 1 week, and 1 month after vaccination. Responses will be compared among vaccine formulations and evaluated according to age and repeated annual vaccination.
Measured: Baseline, 1 week, and 1 month after vaccination, annually for up to 3 years
normalized level of influenza specific secretory IgA in nasal samples
Influenza specific secretory IgA will be measured in nasal samples and normalized to total protein concentration measured using the BCA assay. Normalized secretory IgA levels will be used to assess mucosal immune responses. A pilot assessment will be conducted during the first vaccination season, followed by assessment before and 1 month after vaccination during subsequent annual vaccination seasons to evaluate changes associated with repeated vaccination.
Measured: 1 month after vaccination in the first season; baseline and 1 month after vaccination annually in year 2 and 3
Frequency of influenza specific T cells following vaccination
Influenza specific T cell responses will be assessed by measuring the frequency of antigen responsive T cells following stimulation with influenza antigens. Antigen specific T cells will be characterized using activation induced and functional markers.
Measured: Baseline, 1 week, and 1 month after vaccination, annually for up to 3 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Sep 2026
- Study start21 Sep 2026 (estimated)
- Primary completionDec 2028 (estimated)
- Study completionDec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Influenza VaccinationStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 180 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Korea University Guro Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- National Research Foundation of Korea
- Responsible party
- Principal investigator, Choi, Min Joo, Korea University Guro Hospital
- Investigators
- Joon Young Song, MD, PhD, Study chair, Korea University Guro Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07838298
- Sponsor's protocol ID
- 2026GR0376
- Other IDs
- RS-2026-25468953
- Status last verified
- Sep 2026
- First submitted
- 13 Sep 2026
- Last updated
- 24 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data sharing is not included in the current study protocol and informed consent.