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Respiratory Syncytial Virus (RSV)Phase 1NCT07516418

Study of Different Formulations of Vaccines Encoding the RSV Monovalent Antigen or the Flu H5 Antigen in Participants 18 to 49 Years of Age

A Phase 1 study testing H5 Flu Investigational Medical Product (IMP) 1, H5 Flu IMP 2 and H5 Flu IMP 3 in people with Respiratory Syncytial Virus (RSV) and Influenza A(H5N1), run by Sanofi at 6 sites in Australia.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

The purpose of this study is to evaluate the safety and immunogenicity of different formulations of vaccines encoding the RSV monovalent antigen or the Flu hemagglutinin subtype 5 (H5) antigen in healthy participants aged 18 to 49 years. Read more about this study

Who is it for?
Ages 18 to 49 yearsHealthy volunteers can take part
What is being tested?
H5 Flu Investigational Medical Product (IMP) 1, H5 Flu IMP 2 and H5 Flu IMP 3
Could I receive a placebo?
No, everyone receives an active treatment
How many people
570 participants
Where
6 sitesAustralia
Study dates
15 Apr 2026to 4 Apr 2027
Phase
Phase 1
Are there results?
Not yet: the study is under way

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 49 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Aged 18 to 49 years on the day of inclusion
  • A female participant is eligible to participate if she is not pregnant or breastfeeding and of the following conditions applies:
  • Is of NCBP (Non-Child-Bearing Potential). To be considered of NCBP, a female must be post-menopausal for at least 1 year, or surgically sterile. OR
  • Is of CBP (Child-Bearing Potential) and uses an effective contraceptive method or abstinence from at least 4 weeks prior to study intervention administration until at least 12 weeks after the last study intervention administration.

Who cannot join

  • Any condition which, in the opinion of the Investigator, might interfere with the evaluation of the study objectives
  • 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

6 sites in 1 country. Contact the study team or a site near you to ask about taking part.

Sanofi Trial Transparency Email Recommended (Toll free for US and Canada) contact

800-633-1610 ext. Opt. 6

contact-us@sanofi.com

6 sites in 1 country

Australia6 sites, 6 recruiting

  • Site # 0361002

    Griffith, Queensland, 4222

    Recruiting

  • Site # 0361001

    Herston, Queensland, 4006

    Recruiting

  • Site # 0361003

    Morayfield, Queensland, 4506

    Recruiting

  • Site # 0361005

    Sippy Downs, Queensland, 4556

    Recruiting

  • Site # 03610004

    South Brisbane, Queensland, 4104

    Recruiting

  • Site # 036006

    Taringa, Queensland, 4068

    Recruiting

Other trials in Australia

About this study

Official title: A Phase 1, Randomized, Multi-center Study to Evaluate the Safety and Immunogenicity of Different Formulations of Vaccines Encoding the RSV Monovalent Antigen or the Flu H5 Antigen in Healthy Participants 18 to 49 Years of Age

The purpose of this study is to evaluate the safety and immunogenicity of different formulations of vaccines encoding the RSV monovalent antigen or the Flu hemagglutinin subtype 5 (H5) antigen in healthy participants aged 18 to 49 years.

The total duration of study participation for each participant varies by stage and treatment arm.

Stage 1:

  • For Arm 1, Arm 2, and Arm 3 the duration of study participation will be approximately 7 months for each participant.
  • For Arm 4, Arm 5, and Arm 6 the duration of study participation will be approximately 6 months for each participant.

Stage 2: For all arms, the duration of study participation will be approximately 7 months for each participant.

Being tested
H5 Flu Investigational Medical Product (IMP) 1, H5 Flu IMP 2, H5 Flu IMP 3, RSV IMP 4, RSV IMP 5
Keywords
RSV, RSV Infection, RSV Vaccine, Flu, Flu Infection, Flu Vaccine
Medical subject headings
Respiratory Syncytial Virus Infections, Influenza, Human

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • H5 Flu Investigational Medical Product (IMP) 1Biological

    Suspension for injection. Route of administration: Intramuscular (IM) injection

  • H5 Flu IMP 2Biological

    Suspension for injection. Route of administration: Intramuscular (IM) injection

  • H5 Flu IMP 3Biological

    Suspension for injection. Route of administration: Intramuscular (IM) injection

  • RSV IMP 4Biological

    Suspension for injection. Route of administration: Intramuscular (IM) injection

  • RSV IMP 5Biological

    Suspension for injection. Route of administration: Intramuscular (IM) injection

  • RSV IMP 6Biological

    Suspension for injection. Route of administration: Intramuscular (IM) injection

  • H5 Flu IMP 7Biological

    Suspension for injection. Route of administration: Intramuscular (IM) injection

  • H5 Flu IMP 8Biological

    Suspension for injection. Route of administration: Intramuscular (IM) injection

  • H5 Flu IMP 9Biological

    Suspension for injection. Route of administration: Intramuscular (IM) injection

  • H5 Flu IMP 10Biological

    Suspension for injection. Route of administration: Intramuscular (IM) injection

  • H5 Flu IMP 11Biological

    Suspension for injection. Route of administration: Intramuscular (IM) injection

  • H5 Flu IMP 12Biological

    Suspension for injection. Route of administration: Intramuscular (IM) injection

Study groups in NCT07516418
Study groupRoleWhat they receive
Stage 1, Arm 1ExperimentalParticipants will receive a single IM (Intramuscular) injection on day 1 and day 22 of the H5 Flu vaccines according to their randomization schedule.
Receives: Biological: H5 Flu Investigational Medical Product (IMP) 1
Stage 1, Arm 2ExperimentalParticipants will receive a single IM (Intramuscular) injection on day 1 and day 22 of the H5 Flu vaccines according to their randomization schedule.
Receives: Biological: H5 Flu IMP 2
Stage 1, Arm 3ExperimentalParticipants will receive a single IM (Intramuscular) injection on day 1 and day 22 of the H5 Flu vaccines according to their randomization schedule.
Receives: Biological: H5 Flu IMP 3
Stage 1, Arm 4ExperimentalParticipants will receive a single IM (Intramuscular) injection on day 1 of the RSV vaccines according to their randomization schedule.
Receives: Biological: RSV IMP 4
Stage 1, Arm 5ExperimentalParticipants will receive a single IM (Intramuscular) injection on day 1 of the RSV vaccines according to their randomization schedule.
Receives: Biological: RSV IMP 5
Stage 1, Arm 6ExperimentalParticipants will receive a single IM (Intramuscular) injection on day 1 of the RSV vaccines according to their randomization schedule.
Receives: Biological: RSV IMP 6
Stage 2, Arm 1ExperimentalParticipants will receive a single IM (Intramuscular) injection on day 1 and day 22 of the H5 Flu vaccines according to their randomization schedule.
Receives: Biological: H5 Flu IMP 7
Stage 2, Arm 2ExperimentalParticipants will receive a single IM (Intramuscular) injection on day 1 and day 22 of the H5 Flu vaccines according to their randomization schedule.
Receives: Biological: H5 Flu IMP 8
Stage 2, Arm 3ExperimentalParticipants will receive a single IM (Intramuscular) injection on day 1 and day 22 of the H5 Flu vaccines according to their randomization schedule.
Receives: Biological: H5 Flu IMP 9
Stage 2, Arm 4ExperimentalParticipants will receive a single IM (Intramuscular) injection on day 1 and day 22 of the H5 Flu vaccines according to their randomization schedule.
Receives: Biological: H5 Flu IMP 10
Stage 2, Arm 5ExperimentalParticipants will receive a single IM (Intramuscular) injection on day 1 and day 22 of the H5 Flu vaccines according to their randomization schedule.
Receives: Biological: H5 Flu IMP 11
Stage 2, Arm 6ExperimentalParticipants will receive a single IM (Intramuscular) injection on day 1 and day 22 of the H5 Flu vaccines according to their randomization schedule.
Receives: Biological: H5 Flu IMP 12

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Presence of any unsolicited systemic Adverse Events (AEs) reported within 30 minutes after vaccination

    Measured: On Day 1

  2. Presence of solicited injection site reactions (ie, injection site pain, injection site erythema, injection site swelling, pre-listed in participant's diary and in the eCRF (electronic case report form)) occurring through 7 days after each vaccination

    Measured: Day 1 through day 8

  3. Presence of solicited systemic reactions (ie, fever, headache, and only new or worsened fatigue, myalgia, arthralgia, and chills pre-listed in the participant's diary and in the eCRF) occurring through 7 days after each vaccination

    Measured: Day 1 through day 8

  4. Presence of unsolicited AEs reported through 20 days after the first vaccination and after the second vaccination for IMPs with the Flu H5 antigen

    Measured: Day 1 through day 21

  5. Presence of unsolicited AEs reported through 28 days after vaccination for IMPs with the RSV antigen

    Measured: Day 1 through day 29

  6. Presence of SAEs (Serious Adverse Events) and AESIs (Adverse Events of Special Interest) throughout the study (ie, through 6 months after vaccination)

    Measured: SAE: Screening day through day 202 (IMPs containing Flu H5 antigen), Screening day through day 181 (IMPs containing RSV antigen); AESI: Day 1 through day 202 (IMPs containing Flu H5 antigen), Day 1 through day 181 (IMPs containing RSV antigen)

  7. Presence of out-of-range biological test results (including shift from baseline values) through 7 days after each vaccination

    Measured: Screening through day 8

  8. Presence of AEs leading to study discontinuation throughout the study (ie, through 6 months after vaccination)

    Measured: Screening through day 202 (IMPs containing Flu H5 antigen), Screening through day 181 (IMPs containing RSV antigen)

  9. RSV A and RSV B serum nAb (neutralizing antibodies) titers at pre-vaccination and 28 days post-vaccination in all participants receiving IMPs with the RSV antigen

    Measured: Day 1 and day 29

  10. Flu H5 antibody (Ab) titer measured by hemagglutination inhibition (HAI) at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen

    Measured: Day 1, day 22 and day 43

  11. Hemagglutination Inhibition (HAI) geometric mean titer ratio at 21 and 42 days post-vaccination relative to pre-vaccination for all participants receiving IMPs with the Flu H5 antigen

    Ratio of post-vaccination to pre-vaccination hemagglutination inhibition (HAI) antibody titers, calculated as Day 22/Day 1 and Day 43/Day 1.

    Measured: Day 1, day 22 and day 43

  12. Seroconversion rate based on Hemagglutination inhibition (HAI) antibody titers at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen

    Measured: Day 1, day 22 and day 43

  13. Proportion of participants with Hemagglutination Inhibition (HAI) antibody titer ≥40 at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen

    Measured: Day 1, day 22, and day 43

  14. Proportion of participants with detectable HAI antibody titer ≥10 at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen

    Measured: Day 1, day 22, and day 43

Secondary outcomes (5)

  1. Geometric mean neutralizing antibody titers measured by Neutralization Assay (NT) at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen

    Measured: Day 1, day 22, and day 43

  2. Neutralizing antibody titer ratio at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen

    Ratio of post-vaccination to pre-vaccination neutralizing antibody titers, calculated as Day 22/Day 1 and Day 43/Day 1 using a validated neutralization (NT) assay.

    Measured: Day 1, day 22, and day 43

  3. Proportion of participants with neutralizing antibody titers ≥20, ≥40, and ≥80 at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen

    Measured: Day 1, day 22, and day 43

  4. Proportion of participants with detectable neutralizing antibody titers ≥10 at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen

    Measured: Day 1, day 22, and day 43

  5. Proportion of participants with ≥2-fold and ≥4-fold increase in neutralizing antibody titers at pre-vaccination and 21 and 42 days post-vaccination in all participants receiving IMPs with the Flu H5 antigen

    Measured: Day 1, day 22, and day 43

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted8 Apr 2026
  2. Study start15 Apr 2026
  3. Primary completion4 Apr 2027 (estimated)
  4. Study completion4 Apr 2027 (estimated)

Resources

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
Sequential
Masking
Triple blind
Who is masked
Participant, Care provider, Investigator
Enrolment
570 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07516418
Sponsor's protocol ID
VAV00053
Other IDs
U1111-1322-6386
Status last verified
May 2026
First submitted
31 Mar 2026
Last updated
8 May 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
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

Questions about this trial

What is this clinical trial studying?

A Phase 1 study testing H5 Flu Investigational Medical Product (IMP) 1, H5 Flu IMP 2 and H5 Flu IMP 3 in people with Respiratory Syncytial Virus (RSV) and Influenza A(H5N1), run by Sanofi at 6 sites in Australia.

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 4 inclusion and 2 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: looking for participants now, as of the sponsor's last update on 8 May 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 6 sites in Australia. 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?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Sanofi Trial Transparency Email Recommended (Toll free for US and Canada) (800-633-1610 ext. Opt. 6, contact-us@sanofi.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Presence of any unsolicited systemic Adverse Events (AEs) reported within 30 minutes after vaccination (time frame: On Day 1). The study lists 14 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 NCT07516418.

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 8 May 2026.

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