Recruiting

YF-17D vs. QIV

Sponsor:

Emory University

Code:

NCT05801978

Conditions

Vaccine Response

Eligibility Criteria

Sex: All

Age: 18 - 50

Healthy Volunteers: Accepted

Interventions

Live Attenuated Yellow Fever 17D Vaccine

Quadrivalent seasonal influenza vaccine

Study Details

Brief 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

Study ID

NCT05801978

Start date

Apr 11, 2023

Status verified date

Jul, 2026

Completion date

Sep, 2027

Anticipated

Primary completion date

Sep, 2027

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 50

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Able to understand and give informed consent.
  • Age 18-50 years.
  • Participants agree not to take any live vaccines 30 days before or after (14 days for inactivated) vaccination.
  • Women of child bearing potential must agree to use effective birth control for the first 3 months of the study. A negative urine pregnancy test must be documented prior to vaccination and prior to tissue sampling procedures.

Exclusion Criteria:

  • History of allergy or serious adverse reaction, including Guillain-Barré syndrome, to a vaccine or vaccine products.
  • 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.
  • History of Hepatitis B or Hepatitis C infection.
  • Chronic clinically significant medical problems that could affect the immune response, require medication that would affect the immune response, or have signs or symptoms that could be confused with reactions to vaccination, including (but not limited to):

1. Insulin dependent diabetes
2. Severe heart disease (including arrhythmias)
3. Severe lung disease
4. Severe liver disease
5. Severe kidney disease
6. Grade 4 hypertension (\*Grade 4 hypertension per CTCAE criteria is defined as life-threatening consequences (e.g., malignant hypertension, transient or permanent neurologic deficit))
  • Thymus gland problems (such as myasthenia gravis, DiGeorge syndrome, thymoma) or removal of thymus gland or history of uncontrolled autoimmune disorder.
  • Pregnancy or breast feeding, or plans to become pregnant in the first 3 months of study participation.
  • Receipt of blood products or immune globulin product within the prior 3 months.
  • Active duty military.
  • History of excessive alcohol consumption, drug use, psychiatric conditions, social conditions or occupational conditions that in the opinion of the investigator would preclude compliance with the trial.

Additional Exclusion Criteria for YF-17D Arm

  • History of previous yellow fever, West Nile, Dengue, St. Louis encephalitis, or Japanese encephalitis vaccination or infection.
  • Previous residence in a country where there is a risk of yellow fever virus (YFV) transmission
  • History of allergy to eggs, chicken, or gelatin.

Additional Exclusion Criteria for QIV Arm

  • History of influenza infection within the same influenza season.

Study Design

Enrollment

66 participants

Anticipated

Allocation

Non randomized

Intervention Model

Parallel Assignment

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: YF-17D Vaccination

Yellow Fever Vaccine (YF-17D) vaccination: Eligible participants will be asked to read the Vaccine Information Sheet for YF-17D per the Centers for Disease Control and Prevention (CDC) guidelines. Participants will then receive the YF-17D vaccine. They will be observed for a minimum of 20 minutes for any immediate hypersensitivity reactions. They will also be given the International Certificate of Vaccination documenting receipt of YF-17D.

experimental: QIV Vaccination

Quadrivalent seasonal influenza vaccine (QIV) vaccination: Eligible participants will be asked to read the Vaccine Information Sheet for QIV per the CDC guidelines. Participants will then receive QIV. They will be observed for a minimum of 20 minutes for any immediate hypersensitivity reactions.

Interventions

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.

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.

Primary outcome measure

  • Magnitude of neutralizing antibody (nAB) response against YF-17D in blood [ Time Frame: Up to 270 days after vaccination ]
  • Magnitude of neutralizing antibody (nAb) response against QIV in blood [ Time Frame: Up to 270 days after vaccination ]

Central Contacts and Locations

Central contacts

Nadine Rouphael, MD

404-712-1435nroupha@emory.edu

Locations

Emory University Hospital

Recruiting

Atlanta, Georgia, United States, 30322

Contacts

Nadie Rouphael, MD

404-712-1435nroupha@emory.edu

Emory Winship Cancer Institute

Recruiting

Atlanta, Georgia, United States, 30322

Contacts

Nadine Rouphael, MD

404-712-1435nroupha@emory.edu

The Hope Clinic of Emory University

Recruiting

Decatur, Georgia, United States, 30030

Contacts

Nadine Rouphael, MD

404-712-1435nroupha@emory.edu

More Information

Sponsor

Emory University

Last update posted

Jul 17, 2026

Last verified

Jul, 2026

Keywords

  • Durability
  • Immune Response

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Emory University on 2026-07-17.