A Phase I/II Study Of The Immunogenicity Of The Yellow Fever Vaccine 17D (YFVax®) In Adults With Prior 17D Vaccination
Overview
- Phase
- Phase 1
- Intervention
- 17D
- Conditions
- Yellow Fever
- Sponsor
- Oregon Health and Science University
- Enrollment
- 35
- Locations
- 1
- Primary Endpoint
- Neutralizing antibody titer boost following vaccination
- Status
- Recruiting
- Last Updated
- 9 months ago
Overview
Brief Summary
The goal of this clinical trial is to assess the immune response to the yellow fever vaccine 17D in adults with prior 17D vaccination. The main questions this study aims to answer are:
- how does prior vaccination affect antibody responses to re-vaccination?
- how does prior vaccination affect the immune cell response to re-vaccination?
Participants will:
- have been previously vaccinated with 17D.
- be re-vaccinated with 17D.
- provide medical and travel histories.
- provide a blood sample prior to vaccination
- provide a blood sample approximately every other day for 14 days after vaccination.
- provide a blood sample approximately 28 days after vaccination.
- complete a daily diary of symptoms following vaccination for 14 days.
- report any additional symptoms after 14 days.
Detailed Description
In this study the investigators use 17D revaccination as a live-virus challenge to test the hypothesis that neutralizing antibody titers correlate with YFV protection. The investigators will prospectively characterize pre-boost antibodies titers, vaccine viremia, acute immune responses and post-boost titers in vaccinees receiving boost 17D vaccinations. The investigators expect to identify neutralizing antibody titers above which sterilizing immunity is conferred and titers below which it is not. These Aims will set a foundation for future studies to further dissect determinants of 17D and other live-attenuated vaccine induced immunity and establish metrics that could allow efficient prioritization of 17D vaccination and optimize 17D use in the face of current and future outbreaks.
Investigators
William Messer
Associate Professor
Oregon Health and Science University
Eligibility Criteria
Inclusion Criteria
- •Aged ≥20 to \<50 years.
- •Male or female.
- •In good health at the time of screening as determined by medical history, physical examination, and clinical judgement of the investigator.
- •Documented history of Yellow fever vaccination 8 or more years prior. Documentation must be on a primary (not copied) vaccination card or a fully completed electronic medical record entry including date of administration and lot number administered.
- •Subjects who can comply with all trial procedures and are available for the duration of follow-up.
Exclusion Criteria
- •A clinically active infection or self-reported body temperature ≥38°C (100.4°F) within 3 days of scheduled date of vaccination (consider whether the finding is an exclusion criterion or criterion for delay of vaccination see Section 8.3).
- •A known hypersensitivity or allergy to any of the trial vaccine components including eggs.
- •Behavioral/cognitive impairment that, in the investigator's opinion, may interfere with the subject's ability to participate safely in the trial.
- •Any history of neurologic disorder, seizure disorder or neuro-inflammatory disease.
- •Any illness, or history of any illness that, in the investigator's opinion, could interfere with the trial or pose an additional risk to the subject during the trial period.
- •Known or suspected impairment/alteration of immune function, including:
- •Chronic use of oral steroids within 60 days prior to enrollment. Inhaled steroids are allowed.
- •Receipt of parenteral steroids within 60 days prior to screening visit.
- •Receipt of immunoglobulins and/or any blood products within the 3 months prior to enrollment or planned receipt during the trial.
- •Receipt of immunostimulants within 60 days prior to screening visit
Arms & Interventions
Vaccination arm
Participants will receive a standard dose of of the yellow fever vaccine 17D (YFVax(r)), 0.5mL suspension in normal saline administered subcutaneously once.
Intervention: 17D
Outcomes
Primary Outcomes
Neutralizing antibody titer boost following vaccination
Time Frame: 28 days
four-fold rise in neutralization antibody titer before and after vaccinatioin
vaccine viremia following vaccination
Time Frame: 14 days
detection of vaccine virus in subject blood
Secondary Outcomes
- CD4+ immune cell response to vaccination(28 days)