An observational study in Healthy, sponsored by Rockefeller University. Completed at 1 site in United States. Open to participants aged 18 Years to 59 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-07-14.
Sponsored by Rockefeller University · Observational
The immune system is composed of diverse cell types with different functions that act together in order to defend against infection. This pilot study will test a new technology for studying these many different cell types at very large numbers at the level of individual cells. This method will then be used to identify the cell types and functions important for the immune response to the highly protective yellow fever vaccine, which will improve our understanding of effective vaccine features.
Vaccines have had monumental impact in reducing the mortality and morbidity of infectious disease. However, the underlying immune mechanisms that contribute to their effectiveness are incompletely understood. Transcriptomics (methods that measure the activity of thousands of genes) studies have identified key features of responses to vaccination(see references) and infection(see references). However, these experiments are typically performed on heterogeneous cell mixtures such as peripheral blood mononuclear cells (PBMC which include certain types of white blood cells) and therefore provide an aggregate measure of gene expression from the many different immune cells and their respective activities in the mixture. Such results can obscure important biological information, particularly in minor subsets of active cells. Establishing a method for immune transcriptomics at single cell resolution would be a highly significant advance and enable more informative and functionally relevant systems immunology studies with commonly used sample types (i.e. PBMC). Applying this high-resolution approach to Yellow Fever Vaccine (YFV), an exceptionally effective vaccine, is likely to identify unappreciated mechanisms that contribute to protective immunity.
Rockefeller University is the lead sponsor of 123 studies on the registry; 3 are open to participants now.
Of its 14 completed or terminated interventional studies of FDA-regulated products, 6 (43%) have results posted.
Counted across the registry records on this site, refreshed daily.
Healthy Volunteers
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Healthy participants who receive the Yellow fever vaccine for travel and/or occupational risk will have peripheral blood samples collected longitudinally at time points selected for different immune events post-vaccination according to published studies (Day 0 baseline; Days: 3, 7, 14, and 42).
Drug: Yellow Fever Vaccine
Yellow Fever Vaccine .5 ml
Also known as: YF-Vax
Feasibility and accuracy of inDrop RNA-Seq
The feasibility and accuracy of inDrop RNA-Seq for distinguishing different cell types will be assessed by comparing (for concordance) cell subset population frequency and distribution values determined by inDrop RNA-seq to cell subset population frequency and distribution values determined by flow cytometry immunophenotyping, the present "gold standard" technique.
Time frame: up to 42 days post baseline visit
Utility of inDrop RNA-Seq
The utility of inDrop RNA-Seq for characterizing an immune response will be determined by measuring cell subset frequencies and gene expression profiles at single cell resolution over time following YFV.
Time frame: Days 0, 3, 7, 14, 42
This study is completed, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
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