Influenza Vaccine Immunogenicity in Repeatedly Vaccinated Older Adults
Immunogenicity of Different Influenza Vaccine Strategies in Older Adults in a Repeated Vaccination Setting
- Influenza Vaccination
- Older Adults (65 Years and Older)
- Immunosenescence
- Immunogenicity
- Repeated Vaccination
At a glance
- Phase
- Phase 4
- Study type
- Interventional
- Sponsor
- Korea University Guro Hospital
- Enrolment target
- 180
- Started
- 21 September 2026
- Main results due
- December 2028
- Study sites
- 1
- Registry updated
- 24 September 2026
Can you take part?
- Aged 19 years and over.
- Open to any sex.
- Healthy volunteers can take part.
These are the headline rules only. Every study has a longer list, and whether you are eligible is decided by the research team at the site — never by this page.
Read the full eligibility criteria
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
What this study is about
In the sponsor’s own words, from the registry.
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.
Study sites(1)
Korea University Guro Hospital
Seoul, South Korea
Recruiting
Showing 1 of 1 sites. 1 of the 1 site on this study is recruiting right now — a site can stop enrolling while the study as a whole is still open.
Source: ClinicalTrials.gov record NCT07838298. Trialion does not run this study, is not paid to refer anyone to it, and cannot enrol you. Eligibility is always decided by the research team at the site.
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