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).
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
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
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