Yellow Fever (Healthy Volunteers)Phase 1VYF01NCT04142086
Dose-ranging Study of an Investigational Yellow Fever Candidate Vaccine in Adults
A Phase 1 study testing Yellow fever vaccine (produced on serum-free Vero cells), Dosage 1 vYF vaccine, Yellow fever vaccine (produced on serum-free Vero cells), Dosage 2 vYF vaccine and Yellow fever vaccine (produced on serum-free Vero cells), Dosage 3 vYF vaccine in people with Yellow Fever (Healthy Volunteers), run by Sanofi Pasteur, a Sanofi Company at 1 site in United States.
Trial summary
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… Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Yellow Fever (Healthy Volunteers)
- What is being tested?
- Yellow fever vaccine (produced on serum-free Vero cells), Dosage 1 vYF vaccine, Yellow fever vaccine (produced on serum-free Vero cells), Dosage 2 vYF vaccine and Yellow fever vaccine (produced on serum-free Vero cells), Dosage 3 vYF vaccine
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 73 participants
- Where
- 1 siteUnited States
- Study dates
- 15 Jan 2020to 24 Jun 2021
- Phase
- Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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
Who cannot join
- 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)
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- 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.
Trial locations and contacts
1 site in 1 country.
United States1 site
Investigational Site Number 8400001
Silver Spring, Maryland, 20910
About this study
Official title: Safety, Tolerability, and Immunogenicity Dose-ranging Study of the Investigational Yellow Fever Vacine (vYF) 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.
Read the detailed description
Study duration per participant is approximately 6 months.
- Conditions
- Yellow Fever (Healthy Volunteers)
- Being tested
- Yellow fever vaccine (produced on serum-free Vero cells), Dosage 1 vYF vaccine, Yellow fever vaccine (produced on serum-free Vero cells), Dosage 2 vYF vaccine, Yellow fever vaccine (produced on serum-free Vero cells), Dosage 3 vYF vaccine, Yellow fever vaccine
- Medical subject headings
- Yellow Fever
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Yellow fever vaccine (produced on serum-free Vero cells), Dosage 1 vYF vaccineBiological
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 vaccineBiological
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 vaccineBiological
Pharmaceutical form: Powder and diluent for suspension for injection Route of administration: Subcutaneous
Yellow fever vaccineBiological
Also called YF-VAX
Pharmaceutical form: Powder and diluent for suspension for injection Route of administration: Subcutaneous
| Study group | Role | What they receive |
|---|---|---|
| Group 1 | Experimental | 1 injection of vYF vaccine Dosage 1 Receives: Biological: Yellow fever vaccine (produced on serum-free Vero cells), Dosage 1 vYF vaccine |
| Group 2 | Experimental | 1 injection of vYF vaccine Dosage 2 Receives: Biological: Yellow fever vaccine (produced on serum-free Vero cells), Dosage 2 vYF vaccine |
| Group 3 | Experimental | 1 injection of vYF vaccine Dosage 3 Receives: Biological: Yellow fever vaccine (produced on serum-free Vero cells), Dosage 3 vYF vaccine |
| Group 4 | Active comparator | 1 injection of YF-VAX Receives: Biological: Yellow fever vaccine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of participants with immediate adverse events
Immediate adverse events are any unsolicited systemic adverse events reported in the 30 minutes after vaccination
Measured: Within 30 minutes after vaccination
Number of participants with solicited injection site reactions
Solicited injection site reactions include injection site pain, erythema and swelling
Measured: Within 7 days after vaccination
Number of participants with solicited systemic reactions
Solicited systemic reactions include fever, headache, malaise, and myalgia
Measured: Within 14 days after vaccination
Number of participants with unsolicited adverse events
Unsolicited (spontaneously reported) adverse events not fulfilling criteria for solicited adverse reactions
Measured: Within 28 days after vaccination
Number of participants with Grade 3 fever
Grade 3 fever is defined as temperature ≥ 102.1°F
Measured: Within 28 days after vaccination
Number of participants with serious adverse events
Serious adverse events are collected throughout the study
Measured: From Day 0 to Day 180
Number of participants with hematology and biochemistry out-of-range test results
Hematology and biochemistry values that are out-of-range are assessed
Measured: From Day 0 to Day 14
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
Investigators are provided with guidelines for recognition and assessment of potential viscerotropic and neurotropic events
Measured: Within 28 days after vaccination
Number of participants with seroconversion to YF virus
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.
Measured: From Day 0 to Day 28
Number of participants with neutralizing antibody titers against YF virus above pre-defined threshold
Pre-defined threshold of 10 1/dilution
Measured: From Day 0 to Day 180
Geometric mean titers of neutralizing antibodies against YF virus
Geometric mean titer ratio Day 10/Day 0, Day 14/Day 0, Day 28/Day 0 and Day 180/Day 0
Measured: From Day 0 to Day 180
Number of participants with YF vaccinal viremia
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.
Measured: From Day 0 to Day 14
Level of YF vaccinal viremia
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.
Measured: From Day 0 to Day 14
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Oct 2019
- Study start15 Jan 2020
- Primary completion24 Jun 2021
- Study completion24 Jun 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Yellow Fever (Healthy Volunteers)Studies of the same condition, open and under way.
- More trials run by Sanofi Pasteur, a Sanofi CompanyThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 73 participants (actual)
Sponsor and investigators
- Lead sponsor
- Sanofi Pasteur, a Sanofi Company
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Clinical Sciences & Operations, Study director, Sanofi Pasteur, a Sanofi Company
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04142086
- Sponsor's protocol ID
- VYF01
- Other IDs
- U1111-1217-1958
- Acronym
- VYF01
- Status last verified
- Sep 2025
- First submitted
- 25 Oct 2019
- Last updated
- 22 Sep 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org
Publications
Pagnon A, Carre C, Aguirre M, Chautard E, Gimenez S, Raynal F, Feroldi E, Scott P, Modjarrad K, Vangelisti M, Mantel N. Next generation yellow fever vaccine induces an equivalent immune and transcriptomic profile to the current vaccine: observations from a phase I randomised clinical trial. EBioMedicine. 2024 Oct;108:105332. doi: 10.1016/j.ebiom.2024.105332. Epub 2024 Sep 17.
PubMed 39293214
Study at a glance
From the registry record, last updated by the sponsor on 22 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Safety, Tolerability, and Immunogenicity Dose-ranging Study of the Investigational Yellow Fever Vacine (vYF) Candidate Vaccine in Adults
- ClinicalTrials.gov ID
- NCT04142086
- Acronym / sponsor ID
- VYF01 / VYF01
- Conditions
- Yellow Fever (Healthy Volunteers)
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 73 participants (actual)
- Lead sponsor
- Sanofi Pasteur, a Sanofi CompanyIndustry (pharma, biotech, devices)
- Study start
- 15 Jan 2020 (actual)
- Primary completion
- 24 Jun 2021 (actual)
- Study completion
- 24 Jun 2021 (actual)
- First posted
- 29 Oct 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
Study duration per participant is approximately 6 months.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Group 1 | Experimental | Biological: Yellow fever vaccine (produced on serum-free Vero cells), Dosage 1 vYF vaccine1 injection of vYF vaccine Dosage 1 |
| Group 2 | Experimental | Biological: Yellow fever vaccine (produced on serum-free Vero cells), Dosage 2 vYF vaccine1 injection of vYF vaccine Dosage 2 |
| Group 3 | Experimental | Biological: Yellow fever vaccine (produced on serum-free Vero cells), Dosage 3 vYF vaccine1 injection of vYF vaccine Dosage 3 |
| Group 4 | Active comparator | Biological: Yellow fever vaccine1 injection of YF-VAX |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- 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
Key exclusion criteria (19 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Yellow fever vaccine (produced on serum-free Vero cells), Dosage 1 vYF vaccinePharmaceutical form: Powder and diluent for suspension for injection Route of administration: Subcutaneous | Biological | Group 1 |
| Yellow fever vaccine (produced on serum-free Vero cells), Dosage 2 vYF vaccinePharmaceutical form: Powder and diluent for suspension for injection Route of administration: Subcutaneous | Biological | Group 2 |
| Yellow fever vaccine (produced on serum-free Vero cells), Dosage 3 vYF vaccinePharmaceutical form: Powder and diluent for suspension for injection Route of administration: Subcutaneous | Biological | Group 3 |
| Yellow fever vaccineAlso: YF-VAXPharmaceutical form: Powder and diluent for suspension for injection Route of administration: Subcutaneous | Biological | Group 4 |
Primary outcome
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
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
Number of participants with solicited systemic reactions
Time frame: Within 14 days after vaccination
Solicited systemic reactions include fever, headache, malaise, and myalgia
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
Number of participants with Grade 3 fever
Time frame: Within 28 days after vaccination
Grade 3 fever is defined as temperature ≥ 102.1°F
Number of participants with serious adverse events
Time frame: From Day 0 to Day 180
Serious adverse events are collected throughout the study
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
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
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.
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
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
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.
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.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Sep 2025.
- Derived from this study: PubMed 39293214Pagnon A, Carre C, Aguirre M, Chautard E, Gimenez S, Raynal F, Feroldi E, Scott P, Modjarrad K, Vangelisti M, Mantel N. Next generation yellow fever vaccine induces an equivalent immune and transcriptomic profile to the current vaccine: observations from a phase I randomised clinical trial. EBioMedicine. 2024 Oct;108:105332. doi: 10.1016/j.ebiom.2024.105332. Epub 2024 Sep 17.
- VYF01 Plain Language Results SummaryLink provided by the sponsor.
- Individual participant dataSharing planned: Yes. Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Clinical Sciences & Operations study director
Sanofi Pasteur, a Sanofi Company
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Yellow fever vaccine (produced on serum-free Vero cells), Dosage 1 vYF vaccine, Yellow fever vaccine (produced on serum-free Vero cells), Dosage 2 vYF vaccine and Yellow fever vaccine (produced on serum-free Vero cells), Dosage 3 vYF vaccine in people with Yellow Fever (Healthy Volunteers), run by Sanofi Pasteur, a Sanofi Company at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 19 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 22 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of participants with immediate adverse events (time frame: Within 30 minutes after vaccination). The study lists 13 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04142086, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Sep 2025.