ClinicalTrials.gg
Enrolling by invitationNCT01244802Updated Nov 4, 2024

Characterization of Human Memory Immune Responses to Prior Yellow Fever Vaccination

An observational study in Yellow Fever Vaccine, sponsored by Emory University. Enrolling by invitation at 1 site in United States. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2024-11-04.

Sponsored by Emory University · Observational

Study type
Observational
Model
Other
Time perspective
Cross-sectional
Enrollment
300
Ages
18 Years and older
Sex
All
01

Study summary

The objective of this study is to study immune memory generated against the yellow fever (YFV) vaccine in participants who have previously received the vaccine. Volunteers will not receive vaccine shots; only immune responses to previous yellow fever vaccination will be studied. The study involves one or multiple blood draws.

Read the detailed description

The goal of this study is to characterize immune memory in humans who have previously received yellow fever vaccine. The project is designed to study the magnitude and persistence of both humoral, and cell-mediated immune memory generated post-vaccination. Since aging has an effect on the immune system (eg. decreased thymic output, replacement of hematopoietic cells in the bone marrow with adipocytes), the researchers will analyze the young adults (aged 18-45 years) and the older vaccinees (55 years or older) in separate groups.

The specific aims of the study are to:

  • Determine the phenotypic and functional characterization of memory T cell responses to yellow fever vaccination
  • Determine neutralizing antibody titer after yellow fever vaccination
02

Conditions studied

  • Yellow Fever Vaccine

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03

In context

Yellow Fever

52 studies on the registry are indexed under Yellow Fever; 10 are open to participants now.

Browse Yellow Fever studies →

Lead sponsor

Emory University is the lead sponsor of 1,405 studies on the registry; 225 are open to participants now.

Of its 237 completed or terminated interventional studies of FDA-regulated products, 178 (75%) have results posted.

Counted across the registry records on this site, refreshed daily.

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Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
Yes
Sampling method
Non-probability sample

Study population

Healthy adults between the ages of 18 to 45 years or 55 or above who previously received the yellow fever vaccine

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.

Inclusion criteria

  • Able to understand and give
  • Age 18-45 years (Group 1) or 55 years and above (Group 2) at the time of yellow fever vaccination
  • Documentation (international certificate of vaccination (yellow card) or medical record) indicating receipt of yellow fever vaccine.

Exclusion criteria

Exclusion Criteria:

  • Recipient of any vaccines within 30 days before the study visit (not applicable to older adults)
  • History of a progressive and severe chronic medical condition resulting in impaired immunity (such as diabetes, kidney or liver dysfunction)
  • Required use of medications
  • Reporting , (surface antigen positive) or infections (antibody positive) on the medical/health history form
  • Recipient of a blood product or immune globulin product within 42 days of study visit
  • Reporting pregnancy
Terms in these criteria, in plain language(5)

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.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

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.

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.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

Hepatitis C tests

Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.

After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.

05

Study design

Observational model
Other
Time perspective
Cross-sectional
Enrollment
300 participants (estimated)
Patient registry
No
Biospecimen retention
Samples with dna

Groups and cohorts

  • Group 1: 18 to 45 years of age

    Between the ages of 18 and 45 at the time of yellow fever vaccination

  • Group 2: 55 years of age and above

    Aged 55 or greater at the time of yellow fever vaccination

06

What researchers measure

Primary outcomes

  1. Determine the phenotypic and functional characterization of memory T cell responses to YF vaccination

    This is an exploratory analysis of variation in immune response with time since last yellow fever virus vaccination.

    Time frame: Immune responses will be measured from at least 30 days after yellow fever vaccination.

07

Study locations

1 site
  • The Hope clinic of Emory Vaccine Center
    Decatur, Georgia 30030, United States
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Nov 4, 2024, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT01244802
Lead sponsor
Emory University
Responsible party
Sri Edupuganti (Professor, Emory University) — Principal investigator
First posted
Nov 19, 2010
Start date
Nov 2010
Primary completion
Oct 2029 (estimated)
Completion
Oct 2029 (estimated)
Last update
Nov 4, 2024

Study contacts

Rafi Ahmed, PhD
study chair · Emory University
Srilatha Edupuganti, MD
principal investigator · Emory University

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Interested in this study?

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No contact was published for this record. The registry link below has the sponsor’s details.

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Discussion

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