Human Immune Responses to The Yellow Fever Virus Vaccine


The objective of this study is to study immune memory generated against the yellow fever vaccine (YFV) in participants who recently received the YFV vaccine. Volunteers who are planning to travel to yellow fever endemic areas will be recruited into this study. Volunteers will receive the yellow fever vaccine at the Hope Clinic of Emory University or at their private health care provider's office. Blood tests will be drawn before the vaccination and at upto 8 visits following vaccination. A volunteers's study participation may will last as short as 1 month or as long as one year depending on the immune responses. We plan to compare the immune responses in younger people (18 to 45 years) to that of older people (55 or above).

Full Title of Study: “Human Immune Responses to Yellow Fever Vaccination”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: N/A
    • Intervention Model: Single Group Assignment
    • Primary Purpose: Basic Science
    • Masking: None (Open Label)
  • Study Primary Completion Date: December 2025


  • Biological: Yellow fever vaccine
    • YFV will be given as injection

Arms, Groups and Cohorts

  • Other: vaccine
    • There are no arms for this study. All participants will receive the YFV vaccine if they meet the screening criteria.

Clinical Trial Outcome Measures

Primary Measures

  • 1. Isolation and characterization of yellow fever vaccine (YFV-17D) specific adaptive immune responses: characterize the magnitude and quality of YFV specific T cell responses, antibody secreting cells and memory B cells.
    • Time Frame: Upto 12 months after vaccination
    • Compare the magnitude and quality of YFV-specific immune responses in the younger and older age groups.

Secondary Measures

  • Determine the signatures of innate immune responses: cytokines, chemokines, dendritic cells and microarray analyses on peripheral blood mononuclear cells
    • Time Frame: Upto 12 months after vaccination
    • Compare the magnitude and kinetics of T and B cell responses, antibody secreting cells and memory B cells in the younger and the older age groups.

Participating in This Clinical Trial

Inclusion Criteria

1. Able to understand and give informed consent 2. Age 18-45 years or greater than or equal to 55 years 3. If possible, participants agree not to take any vaccines within 30 days before or 30 days after yellow fever vaccination 4. Women of child bearing potential must agree to use effective birth control throughout the duration of the study. A negative urine pregnancy test must be documented prior to vaccination. Exclusion Criteria:

1. Travel to or having lived in a country/area which is endemic for yellow fever 2. History of previous yellow fever, West Nile, Dengue, St. Louis encephalitis, Japanese encephalitis vaccination or infection 3. Any history of allergy to eggs, chicken or gelatin or to any previous vaccine 4. A history of a medical condition resulting in impaired immunity (such as HIV infection, cancer, particularly leukemia, lymphoma, use of immunosuppressive or antineoplastic drugs or X-ray treatment). Persons with previous skin cancers or cured non-lymphatic tumors are not excluded from the study. 5. History of HIV infection, Hepatitis B or Hepatitis C infection 6. History of any chronic medical conditions that are considered progressive (ex, diabetes, heart disease, lung disease, liver disease, kidney disease, gastrointestinal diseases and uncontrolled hypertension). Use of systemic immunosuppressive medications (ex, prednisone) for 2 weeks or more in the past 3 months 7. History of excessive alcohol consumption, drug abuse, psychiatric conditions, social conditions or occupational conditions that in the opinion of the investigator would preclude compliance with the trial 8. Thymus gland problems (such as myasthenia gravis, DiGeorge syndrome, thymoma) or removal of thymus gland or history of autoimmune disorder. 9. Recipient of a blood products or immune globulin product within 42 days of the vaccination visit 10. Pregnant women and nursing mothers or women who are planning to become pregnant for the study duration 11. Any condition in the opinion of the investigator that would interfere with the proper conduct of the trial

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: 70 Years

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

  • Lead Sponsor
    • Emory University
  • Collaborator
    • National Institutes of Health (NIH)
  • Provider of Information About this Clinical Study
    • Principal Investigator: Sri Edupuganti, MD MPH, Associate Professor – Emory University
  • Overall Official(s)
    • Rafi Ahmed, PhD, Study Chair, Emory University
    • Sri Edupuganti, MD, MPH, Principal Investigator, Emory University

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