Characterization of Human Memory Immune Responses to Prior Yellow Fever Vaccination

Status

Enrolling by invitation

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT01244802

Enrollment

300

Registered

2010-11-19

Start date

2010-11-30

Completion date

2029-10-31

Last updated

2024-11-04

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Yellow Fever Vaccine

Brief 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.

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

Interventions

None listed

Study design

Observational model

OTHER

Time perspective

CROSS_SECTIONAL

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Yes

Inclusion criteria

* Able to understand and give informed consent * 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

* 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 immunosuppressive medications * Reporting HIV, Hepatitis B (surface antigen positive) or Hepatitis C 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

Design outcomes

Primary

Measure	Time frame	Description
Determine the phenotypic and functional characterization of memory T cell responses to YF vaccination	Immune responses will be measured from at least 30 days after yellow fever vaccination.	This is an exploratory analysis of variation in immune response with time since last yellow fever virus vaccination.

Countries

United States

Outcome results