Baseline Assessment of Skin Resident Memory T Cells in Healthy Unvaccinated Participants (NCT07636551) | Clinical Trial Compass
Not Yet RecruitingNot Applicable
Baseline Assessment of Skin Resident Memory T Cells in Healthy Unvaccinated Participants
Belgium40 participantsStarted 2026-06-15
Plain-language summary
In The main GeKoSkimm trial (= A randomized controlled trial to compare the immunogenicity and skin imprinting of intradermal, subcutaneous and intramuscular yellow fever vaccination) the investigators try to understand whether the route of injection (in the muscle, under the skin, or in the skin) when giving the yellow fever vaccine affects the strength of the body's immune response to yellow fever. More in particular the investigators want to know how well the immune responses are retained in the skin, as this is the place where the virus enters the body after a mosquito bite. This will be important for vaccines against infections transmitted via bites of mosquitoes and ticks, such as yellow fever virus. Because this is the first attempt on human samples and only skin samples after vaccination with yellow fever vaccine are available, the investigators want to assess the baseline or background immune response in 'unvaccinated' skin. Therefore, 40 volunteers will be recruited that have not been previously vaccinated against yellow fever and will not receive a yellow fever vaccine during this study. The participant will be requested to provide two skin samples from the upper arm and a blood sample to confirm their vaccination status regarded to yellow fever.
Who can participate
Age range
18 Years – 50 Years
Sex
ALL
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AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* BMI \>/=18,5 kg/m2 and ≤35 kg/m2
* Agreement to share and discuss participant's medical history and medical records when relevant with the study team
* Able and willing to provide written informed consent
* Agreement to refrain from blood donation and other vaccinations during the study
Exclusion Criteria:
* Participants with a confirmed flavivirus infection in the past
* Participants who received a flavivirus vaccination prior to enrolment (e.g. YFV, Japanese encephalitis virus, tick-borne encephalitis virus, Dengue)
* Receipt of any vaccine (licensed or experimental) within 30 days prior to enrolment or during the study
* Active participation in another interventional clinical study with active substance intake or large medical procedures affecting the study procedures during or 1 month prior to enrolment
* Participant has a clinically significant acute illness (this does not include minor illnesses such as diarrhea or mild upper respiratory tract infection) or temperature ≥38.0ºC within 24 hours prior to the visit; inclusion at a later date is permitted at the discretion of the investigator
* Any confirmed or suspected immunosuppressive or immunodeficient state (incl. cancer and human immunodeficiency virus/hepatitis B virus infection); asplenia; recurrent severe infections and use of immunosuppressant medication (including antineoplastic and immunomodulating agents or radiotherapy) within the last 6 months prior to enrolment, except topical or sho…
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?
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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
1
Estimate the baseline number and proportion of skin-resident memory T cells against YFV (YFV-TRM) in the skin of unvaccinated and healthy volunteers against YFV