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COVID-19 ImmunizationPhase 1/2NCT06695117

Study of a Combination Vaccine Comprised of Different Recombinant Spike Antigen Levels of a Matrix-M Adjuvanted Recombinant COVID-19 Vaccine and High-Dose Inactivated Influenza Vaccine in Adult Participants 50 Years of Age and Older

A Phase 1/2 study testing IIV-HD, rC19 (dose 1) and IIV-HD + rC19 (dose 1) in people with COVID-19 Immunization and Influenza Immunization, run by Sanofi at 12 sites in United States.

Completed

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

Official record
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Trial summary

Study VBT00001 is planned to be a Phase 1/2, randomized, modified double-blind, active-controlled, multi-center study to be conducted in approximately 980 adults aged 50 years and older in the United States. Read more about this study

Who is it for?
Ages 50 years and olderHealthy volunteers can take part
Conditions the study is for
COVID-19 Immunization, Influenza Immunization
What is being tested?
IIV-HD, rC19 (dose 1) and IIV-HD + rC19 (dose 1)
Type of treatment
Injection or infusion
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
980 participants
Where
12 sitesUnited States
Study dates
19 Nov 2024to 16 Apr 2026
Phase
Phase 1/2
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 50 years and older
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Aged 50 years or older on the day of inclusion
  • Informed consent form has been signed and dated.
  • Able to attend all scheduled visits and to comply with all study procedures.
  • Participant must be able to receive an injection in the deltoid muscle of both arms.
  • Participant must have completed a primary vaccination series against SARS-CoV-2 and at least 1 booster with a locally authorized or approved COVID-19 vaccine.
  • Aged 50 years or older on the day of inclusion
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  • Participants who are healthy or with pre-existing stable condition (defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 12 weeks before enrollment), as determined by medical evaluation including medical history and physical examination.
  • 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 post-menopausal 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 4 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) on the day of enrollment before the first dose of study intervention.
  • Informed consent form has been signed and dated.
  • Able to attend all scheduled visits and to comply with all study procedures.
  • Participant must be able to receive an injection in the deltoid muscle of both arms.
  • Participant must have completed a primary vaccination series against SARS-CoV-2 and at least 1 booster with a locally authorized or approved COVID-19 vaccine.

Who cannot join

  • Exclusion criteria to be checked at Screening Visit and at Visit 1 (D01):
  • 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 (for glucocorticoids, ≥ 10 milligrams/day of prednisone or equivalent for more than 2 consecutive weeks within the past 3 months).
  • Known systemic hypersensitivity to any of the study intervention components, or history of a life-threatening reaction to the study interventions used in the study or to a product containing any of the same substances .
  • Self-reported thrombocytopenia, contraindicating intramuscular injection, based on investigator's judgment.
  • Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating intramuscular injection, based on investigator's judgment.
  • Chronic illness (1) that, in the opinion of the investigator, is at a stage where it might interfere with study conduct or completion .
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  • Moderate or severe acute illness/infection (according to investigator judgment) or febrile illness (temperature ≥ 100.4°F) on the day of study intervention administration. A prospective participant should not be included in the study until the condition has resolved or the febrile event has subsided.
  • Alcohol, prescription drug, or substance abuse that, in the opinion of the Investigator, might interfere with the study conduct or completion.
  • History of serious adverse reaction to any influenza or COVID-19 vaccines.
  • Personal or family history of Guillain-Barré syndrome.
  • Prior history of myocarditis, pericarditis, or myopericarditis.
  • Prior history of stroke, transient ischemic attack, or stroke risk factors, which may include untreated/uncontrolled hypertension, untreated/uncontrolled hyperlipidemia, active smoking, atrial fibrillation, and additional risk factors, based on investigator's judgment, which may include history of thromboembolic disease, obesity, cardiac structural or valvular abnormality, carotid stent placement, or family history of stroke..
  • Receipt of any vaccine in the 4 weeks preceding study intervention administration or planned receipt of any vaccine prior to the second blood draw (ie, approximately in the 28 days following study intervention administration .
  • Previous vaccination against influenza (in the previous 6 months) with an investigational or marketed vaccine.
  • Previous vaccination against COVID-19 (in the previous 6 months) with an investigational or marketed vaccine OR history of COVID-19 in the previous 6 months .
  • 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 intervention administration) or planned participation during the present study period in another clinical study investigating a vaccine, drug, medical device, or medical procedure.
  • Deprived of freedom by an administrative or court order, or being in an emergency setting, or hospitalized involuntarily.
  • 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.
  • Chronic illness may include, but is not limited to, cardiac disorders, hypertension, pulmonary disease, renal disorders, auto-immune disorders, diabetes mellitus, psychiatric disorders, neurologic disorders, or chronic infection

Trial locations and contacts

12 sites in 1 country.

12 sites in 1 country

United States12 sites

  • Synexus Clinical Research US - Atlanta- Site Number : 8400001

    Atlanta, Georgia, 30328

  • Optimal Research - Texas- Site Number : 8400002

    Austin, Texas, 78705

  • Simon Williamson Clinic - Birmingham- Site Number : 8400003

    Birmingham, Alabama, 35211

  • Synexus Clinical Research- Site Number : 8400004

    Chicago, Illinois, 60602

  • Synexus Clinical Research - St. Louis- Site Number : 8400010

    Creve Coeur, Missouri, 63141

  • Synexus Clinical Research US - Dallas- Site Number : 8400005

    Dallas, Texas, 75234

  • AES - DRS - Optimal Research Alabama - Huntsville Site Number : 8400006

    Huntsville, Alabama, 35802-2568

  • Synexus Clinical Research - New York- Site Number : 8400007

    New York, New York, 10017

  • Synexus Salt Lake City Site Number : 8400008

    Salt Lake City, Utah, 84106

  • Synexus Clinical Research US - San Antonio- Site Number : 8400009

    San Antonio, Texas, 78229

  • Synexus Clinical Research US - The Villages- Site Number : 8400011

    The Villages, Florida, 32162

  • Orange Grove Family Practice- Site Number : 8400012

    Tucson, Arizona, 85741

Other trials in United States

About this study

Official title: A Phase 1/2, Parallel, Randomized, Modified Double-blind, Multi-arm Study to Assess the Safety and Immunogenicity of a Combination Vaccine Comprised of Different Recombinant Spike Antigen Levels of a Matrix-M Adjuvanted Recombinant COVID-19 Vaccine and High-dose Inactivated Influenza Vaccine in Adult Participants 50 Years of Age and Older

Study VBT00001 is planned to be a Phase 1/2, randomized, modified double-blind, active-controlled, multi-center study to be conducted in approximately 980 adults aged 50 years and older in the United States.

The purpose of the study is to assess the safety and immunogenicity of IIV-HD (high-dose inactivated influenza vaccine) + rC19 (adjuvanted recombinant COVID-19 vaccine) vaccine comprised of IIV-HD combined with different recombinant Spike (rS) antigen levels of rC19 compared to IIV-HD alone, rC19 (dose 1) alone, and IIV-HD and rC19 (dose 1) (coadministered in opposite arms).

Read more

Placebo will be coadministered in the IIV-HD alone, rC19 (dose 1) alone, and IIV-HD + rC19 study groups to control for the number of injections and to maintain observer-blinding.

Thus, each participant will receive two injections at enrollment, one in each deltoid muscle.

Study details include:

  • The study duration will be approximately 12 months
  • Study intervention will be administered via a single intramuscular (IM) injection into the right and left deltoid muscles on D01
  • Dose escalation with sequential enrollment (sentinel cohort followed by main cohort for a given dose)
  • The visit frequency will be D01, D09 (telephone call), D30, D182 (telephone call), and D366 (telephone call)

Number of Participants:

Approximately 980 participants are expected to be randomized.

Being tested
IIV-HD, rC19 (dose 1), IIV-HD + rC19 (dose 1), IIV-HD + rC19 (dose 2), IIV-HD + rC19 (dose 3)
Keywords
COVID-19 Vaccine and Influenza Vaccine
Medical subject headings
Influenza, Human

What participants receive

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

  • IIV-HDBiological

    Inactivated, split-virion

  • rC19 (dose 1)Biological

    Protein subunit

  • IIV-HD + rC19 (dose 1)Biological

    IIV-HD component: Inactivated, split-virion rC19 component: Protein subunit

  • IIV-HD + rC19 (dose 2)Biological

    IIV-HD component: Inactivated, split-virion rC19 component: Protein subunit

  • IIV-HD + rC19 (dose 3)Biological

    IIV-HD component: Inactivated, split-virion rC19 component: Protein subunit

  • IIV-HD + rC19 (dose 4)Biological

    IIV-HD component: Inactivated, split-virion rC19 component: Protein subunit

  • Placebo (0.9% NaCl)Other

    Normal saline

Study groups in NCT06695117
Study groupRoleWhat they receive
Group 1: IIV-HD (in right or left deltoid) and placebo (in opposite deltoid)Experimentaltwo IM injections on D01
Receives: Biological: IIV-HD; Other: Placebo (0.9% NaCl)
Group 2: rC19 (dose 1) (in right or left deltoid) and placebo (in opposite deltoid)Experimentaltwo IM injections on D01
Receives: Biological: rC19 (dose 1); Other: Placebo (0.9% NaCl)
Group 3: IIV-HD (in right or left deltoid) and rC19 (dose1) (in opposite deltoid)Experimentaltwo IM injections on D01
Receives: Biological: IIV-HD; Biological: rC19 (dose 1)
Group 4: IIV-HD + rC19 (dose 1) (in right or left deltoid) and placebo (in opposite deltoid)Experimentaltwo IM injections on D01
Receives: Biological: IIV-HD + rC19 (dose 1); Other: Placebo (0.9% NaCl)
Group 5: IIV-HD + rC19 (dose 2) (in right or left deltoid) and placebo (in opposite deltoid)Experimentaltwo IM injections on D01
Receives: Biological: IIV-HD + rC19 (dose 2); Other: Placebo (0.9% NaCl)
Group 6: IIV-HD + rC19 (dose 3) (in right or left deltoid) and placebo (in opposite deltoid)Experimentaltwo IM injections on D01
Receives: Biological: IIV-HD + rC19 (dose 3); Other: Placebo (0.9% NaCl)
Group 7: IIV-HD + rC19 (dose 4) (in right or left deltoid) and placebo (in opposite deltoid)Experimentaltwo IM injections on D01
Receives: Biological: IIV-HD + rC19 (dose 4); Other: Placebo (0.9% NaCl)

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)

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

    Measured: Within 30 minutes after each vaccination

  2. Number of participants with solicited injection site reactions

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

    Measured: Up to 7 each days after vaccination

  3. Number of participants with solicited systemic reactions

    Solicited systemic reactions include fever, headache, fatigue, myalgia and chills

    Measured: Up to 7 days after each vaccination

  4. Number of participants with unsolicited AEs

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

    Measured: Up to 28 days after each vaccination

  5. Number of participants with adverse events of special interest (AESIs)

    AESIs

    Measured: Up to 180 days after each vaccination

  6. Number of participants with medical attended adverse events (MAAEs)

    MAAEs

    Measured: Up to 180 days after each vaccination

  7. Number of MAAEs relating to predefined potential immune-mediated disease (PIMDs)

    MAAEs relating to predefined PIMDs

    Measured: From D182 through 12 months following the last study vaccination

  8. Number of participants with serious adverse events (SAEs)

    SAEs

    Measured: Up to 180 days after each vaccination

  9. Number of participants with related SAEs

    Related SAEs

    Measured: From D182 through 12 months following the last study vaccination

  10. Number of MAAEs relating to predefined PIMDs that meet the criteria for SAEs

    MAAEs relating to predefined PIMDs that meet the criteria for SAEs

    Measured: From D182 through 12 months following the last study vaccination

  11. Geometric mean (GM) of HAI titers in all participants

    HAI titers

    Measured: At D01 and D30

  12. Geometric mean ratio (GMR) HAI titers ratio D30/D01 in all participants

    Individual HAI titers ratio D30/D01

    Measured: At D01 and D30

  13. GM of SARS-CoV-2 neutralizing titers in all participants

    SARS-CoV-2 neutralizing titers

    Measured: At D01 and D30

  14. GMR of SARS-CoV-2 neutralizing titers ratio D30/D01 in all participants

    Individual SARS-CoV-2 neutralizing titers ratio D30/D01

    Measured: At D01 and D30

Secondary outcomes (4)

  1. Percentage of participants with seroconversion in all participants

    Seroconversion is defined by:

    HAI titer < 10 [1/dil] at D01 and post-injection titer ≥ 40 [1/dil] at D30 or HAI titer ≥ 10 [1/dil] and a ≥ 4-fold increase in titer [1/dil] at D30

    Measured: At D30

  2. Percentage of participants with HAI titer ≥ 10 (1/dil) in all participants

    detectable HAI titer ≥ 10 (1/dil)

    Measured: At D01 and D30

  3. Percentage of participants with HAI titer ≥ 40 (1/dil) in all participants

    HAI titer ≥ 40 (1/dil)

    Measured: At D01 and D30

  4. Percentage of participants with seroresponse to SARS-CoV-2 in all participants

    Seroresponse to SARS-CoV-2 is defined by SARS-CoV-2 neutralizing titers ≥ 4-fold rise in SARS-CoV-2 neutralizing titers from D01 to D30

    Measured: At D30

Timeline

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

  1. First posted19 Nov 2024
  2. Study start19 Nov 2024
  3. Primary completion16 Apr 2026
  4. Study completion16 Apr 2026

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 1/2
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
980 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06695117
Sponsor's protocol ID
VBT00001
Other IDs
U1111-1310-5034
Status last verified
Apr 2026
First submitted
14 Nov 2024
Last updated
5 May 2026
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

Questions about this trial

What is this clinical trial studying?

A Phase 1/2 study testing IIV-HD, rC19 (dose 1) and IIV-HD + rC19 (dose 1) in people with COVID-19 Immunization and Influenza Immunization, run by Sanofi at 12 sites 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 16 inclusion and 20 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 5 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 12 sites 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 combined 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.

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

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 each vaccination). 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 NCT06695117.

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 5 May 2026.

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