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Completed

NCT Number: NCT04142086

Dose-ranging Study of an Investigational Yellow Fever Candidate Vaccine in Adults

The primary objectives of the study are:

* To describe the safety profile of each of the 3 dosages of vYF and of YF-VAX® within the 28 days post-vaccination and up to the 6 months (Day 180) post-vaccination visit * To describe the antibody responses elicited by each of the 3 dosages of vYF and by YF-VAX on Day 0 pre-vaccination and then on Day 10, Day 14, Day 28 and 6 months (Day 180) post-vaccination overall and by baseline flavivirus serostatus * To quantify the detectable yellow fever (YF) vaccinal viremia in each vaccine groups (vYF and YF-VAX) in a subset of subjects on Day 0 visit, Day 1 visit, Day 3 visit, Day 5 visit, Day 7 visit, Day 10 visit, and Day 14 visit.

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Key information

Conditions

Yellow Fever (Healthy Volunteers) Arbovirus Infections Flaviviridae Infections Flavivirus Infections Hemorrhagic Fevers, Viral Infections Mosquito-Borne Diseases RNA Virus Infections Vector Borne Diseases Virus Diseases Yellow Fever

Age range

18 year–60 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 1

Primary location

Investigational Site Number 8400001

Silver Spring, Maryland, 20910, United States

About this study

Study duration per participant is approximately 6 months.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Aged 18 years up to 60 years on the day of inclusion
  • Able to read and understand the Informed Consent Form which has been signed and dated
  • Able to attend all scheduled visits and to comply with all trial procedures

Exclusion criteria

  • Participant is pregnant, or lactating, or of childbearing potential and not using an effective method of contraception or abstinence from at least 4 weeks prior to vaccination until at least 4 weeks after vaccination. To be considered of non-childbearing potential, a female must be pre-menarche , or post-menopausal for at least 1 year, or surgically sterile
  • Participation at the time of study enrollment (or in the 4 weeks preceding the trial vaccination) or planned participation during the present trial period in another clinical trial investigating a vaccine, drug, medical device, or medical procedure
  • Receipt of any vaccine in the 4 weeks preceding the trial vaccination or planned receipt of any vaccine in the 4 weeks following the trial vaccination
  • Previous vaccination against a flavivirus disease including YF with either the trial vaccine or another vaccine
  • Receipt of immune globulins, blood, or blood-derived products in the past 6 months
  • Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy, or radiation therapy, within the preceding 6 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months)
  • Known history of flavivirus infection
  • Known systemic hypersensitivity to any of the vaccine components, eggs, or history of a life-threatening reaction to the vaccines used in the trial or to a vaccine containing any of the same substances
  • Known history or laboratory evidence of human immunodeficiency virus infection
  • Known history of hepatitis B or hepatitis C seropositivity
  • Personal of family history of thymic pathology (thymoma, thymectomy, or myasthenia)
  • Deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalized involuntarily
  • Current alcohol abuse or drug addiction
  • Chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with trial conduct or completion, including malignancy, such as leukemia or lymphoma
  • Moderate or severe acute illness/infection (according to investigator judgment) on the day of vaccination or febrile illness (temperature ≥ 100.4 F). A prospective participant should not be included in the study until the condition has resolved or the febrile event has subsided
  • Administration of any anti-viral within 2 months preceding the vaccination and up to the 6 weeks following the vaccination
  • Identified as an Investigator or employee of the Investigator or study center with direct involvement in the proposed study, or identified as an immediate family member (ie, parent, spouse, natural or adopted child) of the Investigator or employee with direct involvement in the proposed study
  • Planned travel in a YF endemic country within 6 months of investigational or control vaccine administration

The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.

Treatment and study plan

Yellow fever vaccine (produced on serum-free Vero cells), Dosage 1 vYF vaccine

Biological

Pharmaceutical form: Powder and diluent for suspension for injection Route of administration: Subcutaneous

Yellow fever vaccine (produced on serum-free Vero cells), Dosage 2 vYF vaccine

Biological

Pharmaceutical form: Powder and diluent for suspension for injection Route of administration: Subcutaneous

Yellow fever vaccine (produced on serum-free Vero cells), Dosage 3 vYF vaccine

Biological

Pharmaceutical form: Powder and diluent for suspension for injection Route of administration: Subcutaneous

Yellow fever vaccine

Biological

Pharmaceutical form: Powder and diluent for suspension for injection Route of administration: Subcutaneous

Other names: YF-VAX

Primary outcomes

  1. Number of participants with immediate adverse events

    Time frame: Within 30 minutes after vaccination

    Immediate adverse events are any unsolicited systemic adverse events reported in the 30 minutes after vaccination

  2. Number of participants with solicited injection site reactions

    Time frame: Within 7 days after vaccination

    Solicited injection site reactions include injection site pain, erythema and swelling

  3. Number of participants with solicited systemic reactions

    Time frame: Within 14 days after vaccination

    Solicited systemic reactions include fever, headache, malaise, and myalgia

  4. Number of participants with unsolicited adverse events

    Time frame: Within 28 days after vaccination

    Unsolicited (spontaneously reported) adverse events not fulfilling criteria for solicited adverse reactions

  5. Number of participants with Grade 3 fever

    Time frame: Within 28 days after vaccination

    Grade 3 fever is defined as temperature ≥ 102.1°F

  6. Number of participants with serious adverse events

    Time frame: From Day 0 to Day 180

    Serious adverse events are collected throughout the study

  7. Number of participants with hematology and biochemistry out-of-range test results

    Time frame: From Day 0 to Day 14

    Hematology and biochemistry values that are out-of-range are assessed

  8. Number of participants with YF and flavivirus viremia and out-of-normal-range biological test results in the event of severe fever, or suspicion of neurotropic disease or acute viscerotropic diseases

    Time frame: Within 28 days after vaccination

    Investigators are provided with guidelines for recognition and assessment of potential viscerotropic and neurotropic events

  9. Number of participants with seroconversion to YF virus

    Time frame: From Day 0 to Day 28

    Seroconversion is defined as a fourfold increase in neutralizing antibody titers as compared to pre-vaccination value. Seroconversion is assessed from Day 0 (pre-vaccination) to Day 10, Day 14 and Day 28.

  10. Number of participants with neutralizing antibody titers against YF virus above pre-defined threshold

    Time frame: From Day 0 to Day 180

    Pre-defined threshold of 10 1/dilution

  11. Geometric mean titers of neutralizing antibodies against YF virus

    Time frame: From Day 0 to Day 180

    Geometric mean titer ratio Day 10/Day 0, Day 14/Day 0, Day 28/Day 0 and Day 180/Day 0

  12. Number of participants with YF vaccinal viremia

    Time frame: From Day 0 to Day 14

    Vaccinal viremia is measured by YF specific quantitative reverse transcription polymerase chain reaction (RT-PCR) assay in samples collected on Day 0, Day 1, Day 3, Day 5, Day 7, Day 10, and Day 14.

  13. Level of YF vaccinal viremia

    Time frame: From Day 0 to Day 14

    Vaccinal viremia is measured by YF specific quantitative RT-PCR assay in samples collected on Day 0, Day 1, Day 3, Day 5, Day 7, Day 10, and Day 14.

Sponsors and collaborators

Lead sponsor

Sanofi Pasteur, a Sanofi Company

Industry

Registry information

Official study title

Safety, Tolerability, and Immunogenicity Dose-ranging Study of the Investigational Yellow Fever Vacine (vYF) Candidate Vaccine in Adults

Acronym: VYF01

Important dates

Study start
2020
Primary completion
2021
Study completion
2021
First posted
Oct 29, 2019
Registry last updated
Sep 22, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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