Yellow FeverPhase 1/2NCT04269265
The Effect of Inflammation and Damage to Lymph Node Structures on Durable Protective Immunity Following Yellow Fever Vaccination
A Phase 1/2 study testing Yellow Fever Vaccine in people with Yellow Fever, run by University of Minnesota at 2 sites in 2 countries.
Trial summary
Hypothesis: Infections other than HIV can cause LN inflammation and collagen damage to the fibroblastic reticular cell network (FRCn), which will lead to CD4 T cell depletion and impaired vaccine responses. Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Yellow Fever
- What is being tested?
- Yellow Fever Vaccine
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 43 participants
- Where
- 2 sitesin 2 countries
- Study dates
- 1 Jul 2020to 23 Oct 2023
- Phase
- Phase 1/2
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 18 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- No contraindication to Yellow Fever vaccine (immunosuppressed for any reason or on an immunosuppressive drug where a live virus vaccine is contraindicated).
- If female of childbearing age must agree to contraception for one month following administration of the vaccination.
Who cannot join
- History of yellow fever or previous vaccination for yellow fever
- Known bleeding disorder
- Prior surgery complicated by clotting abnormality
- Psychiatric or behavioral disorder that, in the opinion of the investigator, will make it difficult for the participant to complete the study
- History of acute hypersensitivity reaction to any component of the vaccine (including gelatin, eggs, egg products, or chicken protein).
- Thymus disorder associated with abnormal immune function
Show all 9Show fewer
- Immunosuppression from any of the following: HIV infection or AIDS, malignant neoplasms, primary immunodeficiencies, transplantation, transplantation, immunosuppressive or immunomodulatory therapy (corticosteroids, alkylating agents, antimetabolites, TNF inhibitors, IL-1 blocking agents, monoclonal antibodies targeting immune cells), previous radiation therapy.
- Pregnant or breastfeeding at the time of vaccination.
- Planning to conceive within 28 days of enrollment and vaccination with the yellow fever vaccine.
Trial locations and contacts
2 sites in 2 countries.
2 sites in 2 countries
United States1 site
University of Minnesota
Minneapolis, Minnesota, 55455
About this study
Hypothesis: Infections other than HIV can cause LN inflammation and collagen damage to the fibroblastic reticular cell network (FRCn), which will lead to CD4 T cell depletion and impaired vaccine responses. This protocol will study yellow fever vaccine (YFV) in two cohorts of people, one from Uganda and the other from Minnesota where we collect lymphoid tissues (LT) and peripheral blood monocytes (PBMCs) before and after vaccination using a new technique to catalog infectious burden of the individual, determine the relationship between IA, Infections, and immune response.
Read the detailed description
The primary aim of this study is to determine the difference between antibody titers in the two study groups and study the relationship between endemic infections, IA, the FRCn, and CD4 and CD8 T cell subsets and the magnitude and durability of neutralizing antibody response to YFV in a cohort shown to have elevated IA, a damaged FRCn, and pan T cell depletion and a cohort that does not. This is a single arm, open-label, two cohort study of healthy adults in Kampala, Uganda and in Minnesota, USA. The cohort in Uganda will be 30 adults (15 men and 15 women) and the cohort in Minnesota will be 16 adults (8 men and 8 women). Everyone will be screened to ensure there are no contraindications to receiving YFV (e.g., immunosuppression) or the planned procedures. The inclusion and exclusion criteria are discussed in detail in the protocol that is included in the appendix. Participants will have an inguinal lymph node and adjacent adipose tissue biopsy and leukapheresis prior to YFV and again 3 weeks after the vaccine administration. The vaccine will be given in the contralateral thigh from the first LN biopsy so that the second biopsy will be from a draining LN. PBMC and plasma as well as urine and stool will be collected at regular intervals over the 18-month follow-up period and leukapheresis will be done again at the month 18 visit.
- Conditions
- Yellow Fever
- Being tested
- Yellow Fever Vaccine
- Medical subject headings
- Yellow Fever
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Yellow Fever VaccineBiological
Also called YF-VAX
YF-VAX®, Yellow Fever Vaccine, for subcutaneous use
| Study group | Role | What they receive |
|---|---|---|
| All Participants | Experimental | In this single-arm study, all participants will receive the intervention Receives: Biological: Yellow Fever Vaccine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Peak Neutralizing Antibody Titer
Peak titer of neutralizing antibody to yellow fever vaccination. Outcome reported as Log YF Antibody titer.
Measured: 18 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Feb 2020
- Study start1 Jul 2020
- Primary completion23 Oct 2023
- Study completion23 Oct 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Yellow FeverStudies 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 1/2
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 43 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Minnesota
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Timothy Schacker, MD, Principal investigator, University of Minnesota
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04269265
- Sponsor's protocol ID
- IDIM-2018-27222
- Other IDs
- U01AI141981
- Status last verified
- Sep 2025
- First submitted
- 11 Feb 2020
- Last updated
- 7 Oct 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 7 Oct 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Inflammation and Damage to Lymph Node Structures on Durable Protective Immunity Following Yellow Fever Vaccination
- ClinicalTrials.gov ID
- NCT04269265
- Acronym / sponsor ID
- IDIM-2018-27222
- Conditions
- Yellow Fever
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 43 participants (actual)
- Lead sponsor
- University of MinnesotaUniversity, hospital or other
- Collaborators
- National Institute of Allergy and Infectious Diseases (NIAID)
- Study start
- 1 Jul 2020 (actual)
- Primary completion
- 23 Oct 2023 (actual)
- Study completion
- 23 Oct 2023 (actual)
- First posted
- 13 Feb 2020 (actual)
- Results
- Posted 7 Oct 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Hypothesis: Infections other than HIV can cause LN inflammation and collagen damage to the fibroblastic reticular cell network (FRCn), which will lead to CD4 T cell depletion and impaired vaccine responses. This protocol will study yellow fever vaccine (YFV) in two cohorts of people, one from Uganda and the other from Minnesota where we collect lymphoid tissues (LT) and peripheral blood monocytes (PBMCs) before and after vaccination using a new technique to catalog infectious burden of the individual, determine the relationship between IA, Infections, and immune response.
Detailed description
The primary aim of this study is to determine the difference between antibody titers in the two study groups and study the relationship between endemic infections, IA, the FRCn, and CD4 and CD8 T cell subsets and the magnitude and durability of neutralizing antibody response to YFV in a cohort shown to have elevated IA, a damaged FRCn, and pan T cell depletion and a cohort that does not. This is a single arm, open-label, two cohort study of healthy adults in Kampala, Uganda and in Minnesota, USA. The cohort in Uganda will be 30 adults (15 men and 15 women) and the cohort in Minnesota will be 16 adults (8 men and 8 women). Everyone will be screened to ensure there are no contraindications to receiving YFV (e.g., immunosuppression) or the planned procedures. The inclusion and exclusion criteria are discussed in detail in the protocol that is included in the appendix. Participants will have an inguinal lymph node and adjacent adipose tissue biopsy and leukapheresis prior to YFV and again 3 weeks after the vaccine administration. The vaccine will be given in the contralateral thigh from the first LN biopsy so that the second biopsy will be from a draining LN. PBMC and plasma as well as urine and stool will be collected at regular intervals over the 18-month follow-up period and leukapheresis will be done again at the month 18 visit.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| All Participants | Experimental | Biological: Yellow Fever VaccineIn this single-arm study, all participants will receive the intervention |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- No contraindication to Yellow Fever vaccine (immunosuppressed for any reason or on an immunosuppressive drug where a live virus vaccine is contraindicated).
- If female of childbearing age must agree to contraception for one month following administration of the vaccination.
Key exclusion criteria (9 listed)
- History of yellow fever or previous vaccination for yellow fever
- Known bleeding disorder
- Prior surgery complicated by clotting abnormality
- Psychiatric or behavioral disorder that, in the opinion of the investigator, will make it difficult for the participant to complete the study
- History of acute hypersensitivity reaction to any component of the vaccine (including gelatin, eggs, egg products, or chicken protein).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Yellow Fever VaccineAlso: YF-VAXYF-VAX®, Yellow Fever Vaccine, for subcutaneous use | Biological | All Participants |
Primary outcome
Peak Neutralizing Antibody Titer
Time frame: 18 months
Peak titer of neutralizing antibody to yellow fever vaccination. Outcome reported as Log YF Antibody titer.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Oct 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No
Related trials for Yellow Fever
RecruitingPhase 3
A Phase III Control Study of the Safety and Immunogenicity of vYF in Pediatric Population
Yellow Fever Immunization
Active, not recruitingPhase 2
Study on an Investigational Yellow Fever Vaccine Compared With YF-VAX in Adults in the USA
Yellow Fever, Healthy Volunteers
Recruiting
Baseline Assessment of Skin Resident Memory T Cells in Healthy Unvaccinated Participants
Yellow Fever (Healthy Volunteers), Biopsy/Methods
Active, not recruitingPhase 2
Study on an Investigational Yellow Fever Vaccine Compared With Stamaril in Adults in Europe and Asia
Yellow Fever
RecruitingObservational study
Risk Assessment of Community Spread of Multiple Endemic Infectious Diseases in a One Health Perspective
Dengue, Chikungunya
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Timothy Schacker, MD principal investigator
University of Minnesota
2 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing Yellow Fever Vaccine in people with Yellow Fever, run by University of Minnesota at 2 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 7 Oct 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in United States, Uganda. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 7 Oct 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Peak Neutralizing Antibody Titer (time frame: 18 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Oct 2025; AzTrials last refreshed its copy on 29 Oct 2026.