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Durability of Vaccine Responses

NCT05801978 · Status: RECRUITING · Phase: PHASE4 · Type: INTERVENTIONAL · Enrollment: 66

Last updated 2026-07-17

No results posted yet for this study

Summary

The ability of the vaccines today to generate a long-lasting protection against infections varies greatly from one vaccine to another. The yellow fever vaccine (YF-17D) is one of the most successful vaccines ever developed, having been administered to over 600 million people globally. A single vaccination is known to induce durable protection over several decades. In contrast, the quadrivalent influenza vaccine (QIV) generates an immunity that wanes quickly with no long-lasting protection. Currently, the duration of immune protection for new vaccines is difficult to predict during vaccine product development and can only be ascertained by a "wait and see" approach. This is due, in part, to the fact that some of the signals that activate a durable immune system protection remain unknown.

This study aims to provide a better understanding of this problem by vaccinating willing participants with either the FDA-approved yellow fever vaccine or the quadrivalent influenza vaccine and collecting baseline and follow-up biologic samples to compare how the immune system reacts.

Conditions

  • Vaccine Response

Interventions

BIOLOGICAL

Live Attenuated Yellow Fever 17D Vaccine

The FDA-approved YF-17D (YF-VAX®) is a live attenuated vaccine manufactured by Sanofi Pasteur as a one-dose vial. The vaccine is prepared by culturing the 17D-204 strain of yellow fever virus, contains sorbitol and gelatin as a stabilizer, and contains no preservative. Each vial of vaccine is supplied with a separate vial of sterile diluent, which contains sodium chloride injection USP (United States Pharmacopeia) without a preservative.

BIOLOGICAL

Quadrivalent seasonal influenza vaccine

The FDA-approved quadrivalent seasonal influenza vaccine contains four distinct strains: two influenza A viruses and two influenza B viruses. The approved seasonal QIV will be purchased from the manufacturer to be given for each season of influenza.

Sponsors & Collaborators

  • Defense Advanced Research Projects Agency

    collaborator FED

  • Open Philanthropy

    collaborator OTHER

  • Emory University

    lead OTHER

Principal Investigators

  • Nadine Rouphael, MD · Emory University

Study Design

Allocation
NON_RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
NONE
Model
PARALLEL

Eligibility

Min Age
18 Years
Max Age
50 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2023-04-11
Primary Completion
2027-09-30
Completion
2027-09-30
FDA Drug
Yes

Countries

  • United States

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT05801978 on ClinicalTrials.gov