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Influenza ImmunizationPhase 1NCT05829356

Substudy 01 - Safety and Immunogenicity of One Monovalent Modified mRNA Vaccine Encoding Influenza Hemagglutinin With LNP, in Adult Participants Aged 18 to 49 Years and 60 Years and Above

A Phase 1 study testing H3 mRNA / LNP Vaccine and Quadrivalent recombinant influenza Vaccine (RIV4) in people with Influenza Immunization, run by Sanofi Pasteur, a Sanofi Company at 8 sites in 2 countries.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

This is a Phase 1, parallel, randomized, active-controlled, multi-center, dose-esclation study with a Master Protocol design which will include several substudies that are developed to evaluate the safety and immunogenicity of different dose levels of modified messenger ribonucleic acid (mRNA) vaccines encoding full… Read more about this study

Who is it for?
Ages 18 years and olderHealthy volunteers can take part
Conditions the study is for
Influenza Immunization
What is being tested?
H3 mRNA / LNP Vaccine and Quadrivalent recombinant influenza Vaccine (RIV4)
Could I receive a placebo?
No, everyone receives an active treatment
How many people
159 participants
Where
8 sitesin 2 countries
Study dates
12 Apr 2023to 14 Mar 2024
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 years and older
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Aged 18 years and above on the day of inclusion
  • Aged 18 years to 49 years or 60 years and above on the day of inclusion (substudy 01)
  • A female participant is eligible to participate if she is not pregnant or breastfeeding and one of the following conditions applies:
  • Is of non-childbearing potential. To be considered of non-childbearing potential, a female must be postmenopausal for at least 1 year, or surgically sterile.
  • OR
  • Is of childbearing potential and agrees to use an effective contraceptive method or abstinence from at least 4 weeks prior to study intervention administration until at least 12 weeks after study intervention administration.
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  • A female participant of childbearing potential must have a negative highly sensitive pregnancy test (urine or serum as required by local regulation) at the screening visit.
  • Participants are eligible for the study only if all of the following criteria are met:
  • A female participant is eligible to participate if she is not pregnant or breastfeeding and one of the following conditions applies:
  • Is of non-childbearing potential. To be considered of non-childbearing potential, a female must be postmenopausal for at least 1 year, or surgically sterile.
  • OR
  • Is of childbearing potential and agrees to use an effective contraceptive method or abstinence from at least 4 weeks prior to study intervention administration until at least 12 weeks after study intervention administration.
  • A female participant of childbearing potential must have a negative highly sensitive pregnancy test (urine or serum as required by local regulation) within 8 hours before the first dose of study intervention.

Who cannot join

  • Previous vaccination against influenza in the previous 6 months with an investigational or marketed vaccine
  • Any screening laboratory parameter with laboratory abnormalities that are greater than Grade 1 or deemed clinically significant in the opinion of the Investigator
  • OR, any screening Liver Function Test (ALT, AST, Bilirubin) > 1.2x Upper Limit of Normal or any other screening laboratory parameter outside of the range of normal limits for age and gender
  • Positive test for human immunodeficiency virus (HIV) antigen and/or antibodies (Abs), hepatitis B (HB) virus surface antigen (HBsAg), hepatitis B core antibodies (HBcAb), or hepatitis C virus antibodies (HCV Abs)
  • 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 systemic hypersensitivity to any of the study intervention components (eg, polyethylene glycol [PEG], polysorbate); history of a life-threatening reaction to the study interventions used in the study or to a product containing any of the same substances; any allergic reaction (eg, anaphylaxis) after administration of mRNA COVID-19 vaccine
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  • Previous history of myocarditis, pericarditis, and/or myopericarditis
  • Screening electrocardiogram (ECG) or troponin value that is consistent with probable or possible myocarditis, pericarditis, and/or myopericarditis or screening ECG that demonstrates clinically relevant abnormalities that may affect participant safety or study results
  • Self-reported thrombocytopenia, contraindicating intramuscular vaccination based on Investigator's judgment
  • Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating intramuscular vaccination based on Investigator's judgment
  • Chronic illness that, in the opinion of the Investigator, is at a stage where it might interfere with study conduct or completion
  • Alcohol, prescription drug, or substance abuse that, in the opinion of the Investigator, might interfere with the study conduct or completion
  • Receipt of any vaccine in the 4 weeks preceding study enrollment or planned receipt of any vaccine in the 4 weeks following study intervention administration
  • Receipt of any mRNA vaccine/product in the 2 months preceding study enrollment or planned receipt of any mRNA vaccine/product within the 2 months following study intervention administration
  • Receipt of immune globulins, blood or blood-derived products in the past 3 months -Participation at the time of study enrollment (or in the 4 weeks preceding study enrollment or planned participation during the present study period in another clinical study investigating a vaccine, drug, medical device, or medical procedure
  • Previous vaccination against influenza in the previous 6 months with an investigational or marketed vaccine
  • Moderate or severe acute illness/infection (according to Investigator's judgment) or febrile illness (temperature ≥ 38.0°C [100.4°F]) on the day of vaccination. A prospective participant should not be included in the study until the condition has resolved or the febrile event has subsided.
  • The above information is not intended to contain all considerations relevant to a potential participation in a clinical trial.

Trial locations and contacts

8 sites in 2 countries.

8 sites in 2 countries

Australia4 sites

  • Investigational Site Number : 0360003

    Adelaide, 5000

  • Investigational Site Number : 0360002

    Camberwell, Victoria, 3124

  • Investigational Site Number : 0360004

    Herston, Queensland, 4006

  • Investigational Site Number : 0360001

    Morayfield, Queensland, 4506

Other trials in Australia

United Kingdom4 sites

  • Investigational Site Number : 8260002

    Leicester, Leicestershire, LE1 5WW

  • Investigational Site Number : 8260001

    London, London, City of, SW10 9NH

  • Investigational Site Number : 8260004

    London, London, City of, W12 0HS

  • Investigational Site Number : 8260003

    Sheffield, Sheffield, S10 2JF

Other trials in United Kingdom

About this study

Official title: A Phase I, Parallel, Randomized, Active-controlled, Multi-center, Dose-escalation Study With Early Safety Data Reviews to Assess Safety and Immunogenicity of One Monovalent Modified Influenza mRNA Vaccine Encapsulated in LNP, in Adults Aged 18 to 49 Years and 60 Years and Above.

This is a Phase 1, parallel, randomized, active-controlled, multi-center, dose-esclation study with a Master Protocol design which will include several substudies that are developed to evaluate the safety and immunogenicity of different dose levels of modified messenger ribonucleic acid (mRNA) vaccines encoding full length hemagglutinin (HA) sequence of influenza virus encapsulated in lipid nanoparticles (LNPs) (hereafter referred to as HA mRNA vaccines) compared to control(s). The HA mRNA vaccine candidates and control(s) are presented in the substudy protocols.

The aim is to generate clinical data across different substudies to provide learnings regarding the mRNA technology to support optimization of the mRNA platform including mRNA and LNP design and to support the decision of LNP and dose selection for future projects using mRNA technology.

The purpose of this Substudy 01 is to evaluate the safety and immunogenicity of a single IM injection of up to 5 dose levels of a monovalent modified mRNA encoding the full-length HA sequence of A/Tasmania/503/2020 (H3N2) influenza virus encapsulated in LNP (hereafter referred to as H3 mRNA /LNP) administered as a single intramuscular (IM) injection in adults 18 to 49 years of age and 60 years of age and above, compared to the following active control: a quadrivalent recombinant influenza vaccine (RIV4).

Read the detailed description

The study duration per participant will be approximately 6 months with 1 injection of one of the different HA mRNA vaccines or control for each substudy and a dose-escalation with sequential enrollment (sentinel cohort followed by main cohort).

Being tested
H3 mRNA / LNP Vaccine, Quadrivalent recombinant influenza Vaccine (RIV4)
Medical subject headings
Influenza, Human

What participants receive

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

  • H3 mRNA / LNP VaccineBiological

    Pharmaceutical Form: Suspension for injection

    Route of Administration: Intra-Muscular

  • Quadrivalent recombinant influenza Vaccine (RIV4)Biological

    Also called Flublok Quadravalent®

    Pharmaceutical Form: Solution for injection in a pre-filled syringe

    Route of Administration: Intra-Muscular

Study groups in NCT05829356
Study groupRoleWhat they receive
Group 1: H3 mRNA /LNP dose 1ExperimentalParticipants will receive one intramuscular (IM) dose of H3 mRNA/LNP at Day 01
Receives: Biological: H3 mRNA / LNP Vaccine
Group 2: H3 mRNA /LNP dose 2ExperimentalParticipants will receive one IM dose of H3 mRNA/LNP at Day 01
Receives: Biological: H3 mRNA / LNP Vaccine
Group 3: H3 mRNA /LNP dose 3ExperimentalParticipants will receive one IM dose of H3 mRNA/LNP at Day 01
Receives: Biological: H3 mRNA / LNP Vaccine
Group 4: H3 mRNA /LNP dose 4ExperimentalParticipants will receive one IM dose of H3 mRNA/LNP at Day 01
Receives: Biological: H3 mRNA / LNP Vaccine
Group 5: H3 mRNA /LNP dose 5ExperimentalParticipants will receive one IM dose of H3 mRNA/LNP at Day 01
Receives: Biological: H3 mRNA / LNP Vaccine
Group 6 (Control Group): RIV4 doseActive comparatorParticipants will receive one IM dose of RIV4 at Day 01
Receives: Biological: Quadrivalent recombinant influenza Vaccine (RIV4)

What is being measured

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

  1. Number of participants with immediate adverse events (AEs)

    Unsolicited systemic AEs that occur within 30 minutes after vaccination

    Measured: Within 30 minutes after vaccination

  2. Number of participants with solicited injection site or systemic reaction

    Number of participants reporting Adverse reactions pre-listed in the protocol and case report form (CRF)

    • Injection site reactions: pain, redness, swelling
    • Systemic reactions: fever, headache, malaise, myalgia, arthralgia, chills

    Measured: Within 7 days from vaccination

  3. Number of participants with unsolicited adverse events

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

    Measured: Up to 28 days after injection

  4. Presence of out-of-range biological test results

    Number of participants with biological safety assessment values out of normal range (as per the laboratory performing the test)

    Measured: At Day 3, Day 9 or Day 29

  5. Presence of serious adverse events (SAEs)

    Number of participants experiencing SAEs

    Measured: Throughout Study (up to approximately Month 6)

  6. Presence of adverse events of special interest (AESIs)

    Number of participants experiencing AESIs

    Measured: Throughout Study (up to approximately Month 6)

  7. Hemagglutination inhibition (HAI) antibody (Ab) response to homologous strain

    Antibody are expressed as geometric mean titers (GMTs) at baseline and post-baseline

    Measured: Day 29

  8. HAI titers at D01

    Antibody titers are expressed as GMTs at baseline and post-baseline

    Measured: Day 1

  9. HAI titers at D29

    Antibody titers are expressed as GMTs at baseline and post-baseline

    Measured: Day 29

  10. Individual HAI Ab titer ratio

    Individual HAI Ab titer ratio will be calculated as: D29/D01

    Measured: Day 1 through Day 29

  11. Number of Participants with Vaccine Response or Seroconversion

    Seroconversion (HAI Ab titer < 10 [1/dil] at D01 and post-injection titer ≥ 40 [1/dil] at D29, or titer ≥ 10 [1/dil] at D01 and a ≥ 4-fold increase in titer [1/dil] at D29)

    Measured: Day 1 through Day 29

  12. 2-fold and 4-fold rise in HAI titers from D01 to D29

    Expressed as percentage post-baseline

    Measured: Day 1 to Day 29

  13. Percentage of participants with detectable antibody HAI titers greater than or equal to (≥) 40 [1/dil]

    Measured: Day 29

  14. Geometric Mean Titers (GMTs) of neutralizing antibody (nAb) titers at Day 1

    Nab titers at Day 1

    Measured: Day 1

  15. Geometric Mean Titers (GMTs) of neutralizing antibody (nAb) titers at Day 29

    Nab titers at Day 29

    Measured: Day 29

  16. Individual nab titer ratio

    Individual nab titer ratio will be calculated as: D29/D01

    Measured: Day 1 through Day 29

  17. 2-fold and 4-fold increase in neutralizing Ab titers from D01 to D29

    Expressed as percentage post-baseline

    Measured: Day 1 to Day 29

Timeline

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

  1. First posted25 Apr 2023
  2. Study start12 Apr 2023
  3. Primary completion14 Mar 2024
  4. Study completion14 Mar 2024

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
Parallel groups
Masking
Double blind
Who is masked
Participant, Investigator
Enrolment
159 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05829356
Sponsor's protocol ID
VAV00019
Other IDs
U1111-1278-3835
Status last verified
Sep 2025
First submitted
6 Apr 2023
Last updated
12 Sep 2025
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 H3 mRNA / LNP Vaccine and Quadrivalent recombinant influenza Vaccine (RIV4) in people with Influenza Immunization, run by Sanofi Pasteur, a Sanofi Company at 8 sites in 2 countries.

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 13 inclusion and 18 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 12 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 8 sites in Australia, United Kingdom. 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 (AEs) (time frame: Within 30 minutes after vaccination). The study lists 17 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 NCT05829356.

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 12 Sep 2025.

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