Respiratory Syncytial Virus ImmunizationPhase 1/2NCT05639894

Study of a Respiratory Syncytial Virus Candidate Encapsulated in a Lipid Nanoparticle Based Formulation in Adults Aged 18 to 50 Years and 60 Years and Older

A Phase 1/2 study testing RSV vaccine candidate in people with Respiratory Syncytial Virus Immunization, run by Sanofi Pasteur, a Sanofi Company at 33 sites in 3 countries.

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

Brief Summary of Stage 1: The purpose of Stage 1 (Phase I/IIa) was to assess the safety and immunogenicity of a single intramuscular (IM) injection of 3 dose-levels of an Respiratory Syncytial Virus (RSV) vaccine candidate formulated with 2 different lipid nanoparticles (LNPs) in healthy adult participants aged… Read more about this study

Who is it for?: Ages 18 years and olderHealthy volunteers can take part
Conditions the study is for: Respiratory Syncytial Virus Immunization
What is being tested?: RSV vaccine candidate
Type of treatment: Vaccines, Injection or infusion
Could I receive a placebo?: Yes, some participants may receive a placebo
How many people: 865 participants
Where: 33 sitesin 3 countries
Study dates: 17 Nov 2022to 2 May 2025
Phase: Phase 1/2
Are there results?: Yes, posted in the registrySummary in the doctors' view

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

Sentinel Cohort Stage 1: Aged 18 to 50 years on the day of inclusion
Main Cohort Stage 1 and Stage 2: Aged 60 years or older on the day of inclusion
Stage 1 and Stage 2:
Sentinel Cohort: A female participant was eligible to participate if she was not pregnant or breastfeeding and:
Was of non-childbearing potential. To be considered of non-childbearing potential, a female must have been postmenopausal for at least 1 year or surgically sterile OR
Was 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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Main and Booster Cohorts: A female participant was eligible to participate if she was not pregnant or breastfeeding and:
Was of non-childbearing potential. To be considered of non-childbearing potential, a female must have been postmenopausal for at least 1 year or surgically sterile.
Able to attend all scheduled visits and to comply with all study procedures
Informed consent form was been signed and dated

Who cannot join

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, 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
History of RSV-associated illness, diagnosed clinically, serologically, or microbiologically in the last 12 months
Previous history of myocarditis, pericarditis, and/or myopericarditis
Thrombocytopenia or bleeding disorder, contraindicating IM injection based on investigator's judgment
Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating intramuscular injection

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Chronic illness that, in the opinion of the investigator, was 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 immune globulins, blood, or blood-derived products in the past 3 months
Receipt of oral or injectable antibiotic therapy within 72 hours prior to the first blood draw
Participation at the time of study enrollment (or in the 4 weeks preceding the first 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 in an emergency setting, or hospitalized involuntarily
Self-reported or documented human immunodeficiency virus (HIV) detected by any FDA-approved/validated test, hepatitis B virus surface antigen (HBsAg), hepatits B core antibodies (HBcAb), or hepatitis C virus antibodies (HCV Abs), or positive SARS-CoV-2 RT-PCR or antigen test
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
The above information was not intended to contain all considerations relevant to a potential participation in a clinical trial.

Trial locations and contacts

33 sites in 3 countries.

Country

City, postcode or hospital

33 sites in 3 countries

United States25 sites

Velocity Clinical Research Site Number : 8400019
Cincinnati, Ohio, 45242
Velocity Clinical Research Site Number : 8400017
Cleveland, Ohio, 44122
Aventiv Research Columbus Site Number : 8400007
Columbus, Ohio, 43213
Velocity Clinical Research - Providence Site Number : 8400006
East Greenwich, Rhode Island, 02818
Cenexel Research Centers of America Site Number : 8400024
Hollywood, Florida, 33024
DM Clinical Research - CyFair Site Number : 8400025
Houston, Texas, 77065
Optimal Research Alabama Site Number : 8400032
Huntsville, Alabama, 35802
Velocity Clinical Research - San Diego - ERN - PPDS Site Number : 8400010
La Mesa, California, 91942
Be Well Clinical Studies Site Number : 8400036
Lincoln, Nebraska, 68516
Velocity Clinical Research, Medford Site Number : 8400014
Medford, Oregon, 97504
Aventiv Research Mesa Site Number : 8400020
Mesa, Arizona, 85210
Suncoast Research Associates, LLC Site Number : 8400003
Miami, Florida, 33173
Lynn Institute of Norman Site Number : 8400023
Norman, Oklahoma, 73072
Coastal Carolina Research Center Site Number : 8400015
North Charleston, South Carolina, 29405
CVS Health - Peoria Site Number : 8400042
Peoria, Arizona, 85381
AES Peoria Site Number : 8400030
Peoria, Illinois, 61614
CVS Health - Phoenix Site Number : 8400041
Phoenix, Arizona, 85019
Centricity Research - Georgia Site Number : 8400009
Rincon, Georgia, 31326
DM Clinical Research - Chicago Site Number : 8400027
River Forest, Illinois, 60305
Peninsula Research Associates Site Number : 8400013
Rolling Hills Estates, California, 90274
Be Well Clinical Studies -Round Rock Site Number : 8400038
Round Rock, Texas, 78681
IMA Clinical Research-San Antonio Site Number : 8400039
San Antonio, Texas, 78229
CVS Health - Thousand Oaks Site Number : 8400043
Thousand Oaks, California, 91361
Martin Diagnostic Clinic Site Number : 8400026
Tomball, Texas, 77375
Velocity Clinical Research Site Number : 8400018
West Jordan, Utah, 84088-8865

Other trials in United States

Puerto Rico5 sites

Investigational Site Number : 6300004
Carolina, 984
Investigational Site Number : 6300003
Guayama, 000784
Investigational Site Number : 6300005
Guaynabo, 00968
Investigational Site Number : 6300001
San Juan, 00909
Investigational Site Number : 6300002
San Juan, 00918

Other trials in Puerto Rico

Australia3 sites

Investigational Site Number : 0360003
Botany, New South Wales, 2019
Investigational Site Number : 0360002
Camberwell, Victoria, 3124
Investigational Site Number : 0360001
Southport, 4215

Other trials in Australia

About this study

Official title: A Phase I/IIa, Randomized, Placebo-controlled Multi-arm Dose-finding Study to Evaluate the Safety and Immunogenicity of a RSV Vaccine Candidate in Adult Participants 18 to 50 Years of Age in Phase I, and 60 Years and Older in Phase IIa

Brief Summary of Stage 1:

The purpose of Stage 1 (Phase I/IIa) was to assess the safety and immunogenicity of a single intramuscular (IM) injection of 3 dose-levels of an Respiratory Syncytial Virus (RSV) vaccine candidate formulated with 2 different lipid nanoparticles (LNPs) in healthy adult participants aged between 18 to 50 years, and 60 years and older. The primary objectives of this stage were to assess the safety and immunogenicity profiles across the dose-level groups (low, medium, and high doses) with 2 LNPs. This stage evaluated the safety and immunogenicity of a booster vaccination administered 12 months after the primary vaccination in a subset of the study population.

Brief Summary of Stage 2:

The study also incorporated a Stage 2 (Phase IIa, dose-ranging design) that included adults aged 60 years and older to assess the safety and immunogenicity of different doses of RSV vaccine encapsulated in one of the LNPs. In the Phase IIa dose-ranging stage, eligible participants were randomly assigned in a 1:1:1 ratio to receive a single IM administration of RSV vaccine candidate doses, or placebo. Multiple safety analyses were performed, minimally at D07 and D28.

Read the detailed description

Stage 1:

The duration of each participant's participation was 12 months for the Sentinel and Main Cohorts, 24 months overall for the subset of participants enrolled in the Booster Cohort.

Treatment Duration:

Sentinel Cohort: 1 intra-muscular (IM) injection. Participants were followed for 12 months post-vaccination.
Main Cohort: 1 IM injection. Participants were followed for 12 months post-vaccination.
Booster Cohort: 1 IM injection 12 months after the primary vaccination. Participants were followed for 12 months after administration of the booster dose.

Stage 2:

The duration of each participant's participation was approximately 6 months.

Treatment Duration:

1 IM injection. Participants were followed for approximately 6 months post vaccination

Conditions: Respiratory Syncytial Virus Immunization
Being tested: RSV vaccine candidate, Placebo

What participants receive

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

RSV vaccine candidateBiological
Pharmaceutical Form: Liquid frozen solution in a vial Route of Administration: Intramuscular injection
PlaceboOther
Pharmaceutical Form: Liquid Route of Administration: Intramuscular injection

Study groups in NCT05639894
Study group	Role	What they receive
Stage 1: Sentinel Cohort: RSV Vaccine Dose A1	Experimental	Participants enrolled in the Sentinel Cohort received 0.5 mL RSV vaccine dose A1 as an IM injection on Day 1 of Stage 1. Receives: Biological: RSV vaccine candidate
Stage 1: Sentinel Cohort: RSV Vaccine Dose A2	Experimental	Participants enrolled in the Sentinel Cohort received 0.5 mL RSV vaccine dose A2 as an IM injection on Day 1 of Stage 1. Receives: Biological: RSV vaccine candidate
Stage 1: Sentinel Cohort: RSV Vaccine Dose B1	Experimental	Participants enrolled in the Sentinel Cohort received 0.5 mL RSV vaccine dose B1 as an IM injection on Day 1 of Stage 1. Receives: Biological: RSV vaccine candidate
Stage 1: Sentinel Cohort: RSV Vaccine Dose B2	Experimental	Participants enrolled in the Sentinel Cohort received 0.5 mL RSV vaccine dose B2 as an IM injection on Day 1 of Stage 1. Receives: Biological: RSV vaccine candidate
Stage 1: Sentinel Cohort: RSV Vaccine Dose C1	Experimental	Participants enrolled in the Sentinel Cohort received 0.5 mL RSV vaccine dose C1 as an IM injection on Day 1 of Stage 1. Receives: Biological: RSV vaccine candidate
Stage 1: Sentinel Cohort: RSV Vaccine Dose C2	Experimental	Participants enrolled in the Sentinel Cohort received 0.5 mL RSV vaccine dose C2 as an IM injection on Day 1 of Stage 1. Receives: Biological: RSV vaccine candidate
Stage 1: Sentinel Cohort: Placebo	Placebo comparator	Participants enrolled in the Sentinel Cohort received 0.5 mL placebo matched to RSV vaccine as an IM injection on Day 1 of Stage 1. Receives: Other: Placebo
Stage 1: Main Cohort: RSV Vaccine Dose A1	Experimental	Participants enrolled in the Main Cohort received 0.5 mL RSV vaccine dose A1 as an IM injection on Day 1 of Stage 1. Receives: Biological: RSV vaccine candidate
Stage 1: Main Cohort: RSV Vaccine Dose A2	Experimental	Participants enrolled in the Main Cohort received 0.5 mL RSV vaccine dose A2 as an IM injection on Day 1 of Stage 1. Receives: Biological: RSV vaccine candidate
Stage 1: Main Cohort: RSV Vaccine Dose B1	Experimental	Participants enrolled in the Main Cohort received 0.5 mL RSV vaccine dose B1 as an IM injection on Day 1 of Stage 1. Receives: Biological: RSV vaccine candidate
Stage 1: Main Cohort: RSV Vaccine Dose B2	Experimental	Participants enrolled in the Main Cohort received 0.5 mL RSV vaccine dose B2 as an IM injection on Day 1 of Stage 1. Receives: Biological: RSV vaccine candidate
Stage 1: Main Cohort: RSV Vaccine Dose C1	Experimental	Participants enrolled in the Main Cohort received 0.5 mL RSV vaccine dose C1 as an IM injection on Day 1 of Stage 1. Receives: Biological: RSV vaccine candidate
Stage 1: Main Cohort: RSV Vaccine Dose C2	Experimental	Participants enrolled in the Main Cohort received 0.5 mL RSV vaccine dose C2 as an IM injection on Day 1 of Stage 1. Receives: Biological: RSV vaccine candidate
Stage 1: Main Cohort: Placebo	Placebo comparator	Participants enrolled in the Main Cohort received 0.5 mL placebo matched to RSV vaccine as an IM injection on Day 1 of Stage 1. Receives: Other: Placebo
Stage 2: RSV Vaccine Dose C2	Experimental	Participants received 0.5 mL RSV vaccine dose C2 as an IM injection on Day 1 of Stage 2. Receives: Biological: RSV vaccine candidate
Stage 2: RSV Vaccine Dose D	Experimental	Participants received 0.5 mL RSV vaccine dose D as an IM injection on Day 1 of Stage 2. Receives: Biological: RSV vaccine candidate
Stage 2: Placebo	Placebo comparator	Participants received 0.5 mL placebo matched to RSV vaccine as an IM injection on Day 1 of Stage 2. Receives: Other: Placebo

What is being measured

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

Stage 1 (Sentinel and Main Cohort) and Stage 2: Number of Participants With Immediate Unsolicited Systemic Adverse Events (AEs)
An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study vaccine, whether or not considered related to the study vaccine. Immediate events were recorded to capture medically relevant unsolicited systemic AEs which occurred within the first 30 minutes after vaccination. An unsolicited AE was an observed AE that did not fulfill the conditions of solicited reactions, i.e., pre-listed in the case report form (CRF) in terms of diagnosis and onset window post-vaccination.
Measured: Up to 30 minutes post-primary vaccination on Day 1
Stage 1 (Sentinel and Main Cohort) and Stage 2: Number of Participants With Solicited Injection Site Reactions and Systemic Reactions
An injection site reaction was an adverse reaction (AR) at and around the injection site of the study vaccine. Injection site reactions were commonly inflammatory reactions. Solicited injection site reactions were reactions at and around the injection site of the study vaccine observed and reported under the conditions (nature and onset) pre-listed in the protocol and CRF. Solicited systemic reactions were systemic AEs observed and reported under the conditions (nature and onset) pre-listed in the protocol and CRF. Solicited reactions were considered to be related to the study vaccine administered.
Measured: From Day 1 (first dose of primary vaccination) up to Day 8 (7 days post-primary vaccination on Day 1)
Stage 1 (Sentinel and Main Cohort) and Stage 2: Number of Participants With Unsolicited Adverse Events
An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study vaccine, whether or not considered related to the study vaccine. An unsolicited AE was an observed AE that did not fulfill the conditions of solicited reactions, i.e., pre-listed in the CRF in terms of diagnosis and onset window post-vaccination.
Measured: From Day 1 (first dose of primary vaccination) up to Day 29 (28 days post-primary vaccination on Day 1)
Stage 1 (Sentinel and Main Cohort): Number of Participants With Medically Attended Adverse Events (MAAEs)
An MAAE was a new-onset or a worsening of a condition that prompted the participant to seek unplanned medical advice at a physician's office or Emergency Department.
Measured: From Day 1 (first dose of primary vaccination) up to Day 29 (28 days post-primary vaccination on Day 1)
Stage 2: Number of Participants With Medically Attended Adverse Events
An MAAE was a new-onset or a worsening of a condition that prompted the participant to seek unplanned medical advice at a physician's office or Emergency Department.
Measured: From Day 1 (first dose of primary vaccination) to Day 180
Stage 1 (Sentinel and Main Cohort) and Stage 2: Number of Participants With Serious Adverse Events (SAEs) and Adverse Events of Special Interest (AESIs)
An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study vaccine, whether or not considered related to the study vaccine. An SAE was defined as any AE that at any dose resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, or was an important medical event. An AESI (serious or non-serious) was 1 of scientific and medical concern specific to the Sponsor's study vaccine or program, for which ongoing monitoring and rapid communication by the investigator to the Sponsor was appropriate.
Measured: From Day 1 (first dose of primary vaccination) to Day 365 (Stage 1 Sentinel and Main Cohorts); From Day 1 (first dose of primary vaccination) to Day 180 (Stage 2)
Stage 1 (Sentinel and Main Cohort) and Stage 2: Number of Participants With Shifts From Baseline to Out-of-Range Biological Test Results
Clinical evaluation of laboratory parameters (hematology, clinical chemistry and coagulation parameters) was performed to determine out-of-range values (below or above normal range). Number of participants with a shift from baseline to out-of-range value within 7 days after primary vaccination (Day 8) are reported. Laboratory parameters with a notable shift from baseline included: hematology: hemoglobin, white blood cells (WBC), red blood cells (RBC); clinical chemistry: blood urea nitrogen (BUN), potassium, glucose, C-reactive protein (CRP), direct bilirubin, troponin I; and coagulation parameters: partial thromboplastin time (PTT).
Measured: From baseline (Day -14 to Day -1) up to Day 8 (7 days post-primary vaccination on Day 1)
Stage 1 (Sentinel and Main Cohort): Geometric Mean Titers (GMTs) of Neutralizing Antibodies Against Respiratory Syncytial Virus A
Neutralizing antibodies activity against RSV A was measured using the RSV plaque reduction neutralization test (PRNT) (micro-PRNT). RSV A serum neutralizing antibodies titers were expressed as 1/dilution.
Measured: Day 1 (pre-primary vaccination) and Day 29 (28 days post-primary vaccination on Day 1)
Stage 2: Geometric Mean Titers of Neutralizing Antibodies Against Respiratory Syncytial Virus A and Respiratory Syncytial Virus B
Neutralizing antibodies activity against RSV A and RSV B was measured using the RSV PRNT (micro-PRNT). RSV A and RSV B serum neutralizing antibodies titers were expressed as 1/dilution.
Measured: Day 1 (pre-primary vaccination) and Day 29 (28 days post-primary vaccination on Day 1)

Secondary outcomes (10)

Stage 1 (Booster Cohort): Number of Participants With Immediate Unsolicited Systemic Adverse Events
An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study vaccine, whether or not considered related to the study vaccine. Immediate events were recorded to capture medically relevant unsolicited systemic AEs which occurred within the first 30 minutes after vaccination. An unsolicited AE was an observed AE that did not fulfill the conditions of solicited reactions, i.e., pre-listed in the CRF in terms of diagnosis and onset window post-vaccination.
Measured: Up to 30 minutes post-booster vaccination at Month 12
Stage 1 (Booster Cohort): Number of Participants With Solicited Injection Site Reactions and Systemic Reactions
An injection site reaction was an AR at and around the injection site of the study vaccine. Injection site reactions were commonly inflammatory reactions. Solicited injection site reactions were reactions at and around the injection site of the study vaccine observed and reported under the conditions (nature and onset) pre-listed in the protocol and CRF. Solicited systemic reactions were systemic AEs observed and reported under the conditions (nature and onset) pre-listed in the protocol and CRF. Solicited reactions were considered to be related to the study vaccine administered.
Measured: Up to 7 days post-booster vaccination at Month 12
Stage 1 (Booster Cohort): Number of Participants With Unsolicited Adverse Events and Medically Attended Adverse Events
An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study vaccine, whether or not considered related to the study vaccine. An unsolicited AE was an observed AE that did not fulfill the conditions of solicited reactions, i.e., pre-listed in the CRF in terms of diagnosis and onset window post-vaccination. An MAAE was a new-onset or a worsening of a condition that prompted the participant to seek unplanned medical advice at a physician's office or Emergency Department.
Measured: Up to 28 days post-booster vaccination at Month 12
Stage 1 (Booster Cohort): Number of Participants With Serious Adverse Events and Adverse Events of Special Interest
An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study vaccine, whether or not considered related to the study vaccine. An SAE was defined as any AE that at any dose resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, or was an important medical event. An AESI (serious or non-serious) was 1 of scientific and medical concern specific to the Sponsor's study vaccine or program, for which ongoing monitoring and rapid communication by the investigator to the Sponsor was appropriate.
Measured: From Month 12 (first dose of booster vaccination) to Month 24
Stage 1 (Booster Cohort): Number of Participants With Shifts From Baseline to Out-of-Range Biological Test Results
Clinical evaluation of laboratory parameters (hematology and clinical chemistry) was performed to determine out-of-range values (below or above normal range). Number of participants with a shift from baseline to out-of-range value within 7 days after booster vaccination (Month 12 + 7 days) are reported. Laboratory parameters with a notable shift from baseline included: hematology: RBC; clinical chemistry: potassium, glucose, direct bilirubin.
Measured: From baseline (Month 12: Day -14 to Day -1) up to 7 days post-booster vaccination at Month 12
Stage 1 (Sentinel and Main Cohort): Geometric Mean Titers of Neutralizing Antibodies Against Respiratory Syncytial Virus A
Neutralizing antibodies activity against RSV A was measured using the RSV PRNT (micro-PRNT). RSV A serum neutralizing antibodies titers were expressed as 1/dilution.
Measured: 3, 6, and 12 months post-primary vaccination on Day 1
Stage 1 (Sentinel and Main Cohort): Geometric Mean Concentration of Binding Antibodies Against Respiratory Syncytial Virus Anti-F Immunoglobulin G (IgG)
Binding antibodies activity against RSV anti-F IgG was measured using enzyme-linked immunosorbent assay (ELISA). Geometric mean concentrations were expressed as endotoxin units per milliliter (EU/mL).
Measured: Day 1 (pre-primary vaccination), Day 29, and 3, 6, and 12 months post-primary vaccination on Day 1
Stage 1 (Booster Cohort): Geometric Mean Titers of Neutralizing Antibodies Against Respiratory Syncytial Virus A
Neutralizing antibodies activity against RSV A was measured using the RSV PRNT (micro-PRNT). RSV A serum neutralizing antibodies titers were expressed as 1/dilution.
Measured: Month 12 (pre-booster vaccination), and 28 days (Month 13), 3 months (Month 15), 6 months (Month 18), and 12 months (Month 24) post-booster vaccination at Month 12
Stage 1 (Booster Cohort): Geometric Mean Concentration of Binding Antibodies Against Respiratory Syncytial Virus Anti-F Immunoglobulin G
Binding antibodies activity against RSV anti-F IgG was measured using ELISA. Geometric mean concentrations were expressed as EU/mL.
Measured: Month 12 (pre-booster vaccination), and 28 days (Month 13), 3 months (Month 15), 6 months (Month 18), and 12 months (Month 24) post-booster vaccination on Month 12
Stage 2: Geometric Mean Concentration of Binding Antibodies Against Respiratory Syncytial Virus Anti-F Immunoglobulin G
Binding antibodies activity against RSV anti-F IgG was measured using ECL assay. Geometric mean concentrations were expressed as arbitrary units (AU)/mL.
Measured: Day 1 (pre-primary vaccination) and Day 29 (28 days post-primary vaccination on Day 1)

Timeline

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

17 Nov 20222 May 2025

First posted7 Dec 2022
Study start17 Nov 2022
Primary completion2 May 2025
Study completion2 May 2025

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for Respiratory Syncytial Virus ImmunizationStudies 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 1/2
Primary purpose: Prevention
Allocation: Randomised
Intervention model: Parallel groups
Model description: Sequential (Phase I)/ parallel (Phase IIa)
Masking: Quadruple blind
Who is masked: Participant, Care provider, Investigator, Outcomes assessor
Enrolment: 865 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT05639894
Sponsor's protocol ID: VAE00010
Other IDs: U1111-1271-1514, 2023-505343-40, 2023
Status last verified: Jul 2026
First submitted: 17 Nov 2022
Last updated: 5 Aug 2026
Results posted: Yes, on ClinicalTrials.gov
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

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

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All Respiratory Syncytial Virus Immunization trials

Study at a glance

From the registry record, last updated by the sponsor on 5 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A Phase I/IIa, Randomized, Placebo-controlled Multi-arm Dose-finding Study to Evaluate the Safety and Immunogenicity of a RSV Vaccine Candidate in Adult Participants 18 to 50 Years of Age in Phase I, and 60 Years and Older in Phase IIa
ClinicalTrials.gov ID: NCT05639894
Acronym / sponsor ID: VAE00010
Conditions: Respiratory Syncytial Virus Immunization
Phase: Phase 1/2
Study type: Interventional
Recruitment status: Completed
Enrolment: 865 participants (actual)
Lead sponsor: Sanofi Pasteur, a Sanofi CompanyIndustry (pharma, biotech, devices)
Study start: 17 Nov 2022 (actual)
Primary completion: 2 May 2025 (actual)
Study completion: 2 May 2025 (actual)
First posted: 7 Dec 2022 (actual)
Results: Posted 5 Aug 2026

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Brief Summary of Stage 1:

Brief Summary of Stage 2:

Detailed description

Stage 1:

The duration of each participant's participation was 12 months for the Sentinel and Main Cohorts, 24 months overall for the subset of participants enrolled in the Booster Cohort.

Treatment Duration:

Sentinel Cohort: 1 intra-muscular (IM) injection. Participants were followed for 12 months post-vaccination.
Main Cohort: 1 IM injection. Participants were followed for 12 months post-vaccination.
Booster Cohort: 1 IM injection 12 months after the primary vaccination. Participants were followed for 12 months after administration of the booster dose.

Stage 2:

The duration of each participant's participation was approximately 6 months.

Treatment Duration:

1 IM injection. Participants were followed for approximately 6 months post vaccination

Study design

Primary purpose: Prevention
Allocation: Randomised
Intervention model: Parallel groups
Masking: Quadruple blind (participant, care provider, investigator, outcomes assessor)
Number of arms: 17
Model description: Sequential (Phase I)/ parallel (Phase IIa)

Arm	Type	Receives
Stage 1: Sentinel Cohort: RSV Vaccine Dose A1	Experimental	Biological: RSV vaccine candidateParticipants enrolled in the Sentinel Cohort received 0.5 mL RSV vaccine dose A1 as an IM injection on Day 1 of Stage 1.
Stage 1: Sentinel Cohort: RSV Vaccine Dose A2	Experimental	Biological: RSV vaccine candidateParticipants enrolled in the Sentinel Cohort received 0.5 mL RSV vaccine dose A2 as an IM injection on Day 1 of Stage 1.
Stage 1: Sentinel Cohort: RSV Vaccine Dose B1	Experimental	Biological: RSV vaccine candidateParticipants enrolled in the Sentinel Cohort received 0.5 mL RSV vaccine dose B1 as an IM injection on Day 1 of Stage 1.
Stage 1: Sentinel Cohort: RSV Vaccine Dose B2	Experimental	Biological: RSV vaccine candidateParticipants enrolled in the Sentinel Cohort received 0.5 mL RSV vaccine dose B2 as an IM injection on Day 1 of Stage 1.
Stage 1: Sentinel Cohort: RSV Vaccine Dose C1	Experimental	Biological: RSV vaccine candidateParticipants enrolled in the Sentinel Cohort received 0.5 mL RSV vaccine dose C1 as an IM injection on Day 1 of Stage 1.
Stage 1: Sentinel Cohort: RSV Vaccine Dose C2	Experimental	Biological: RSV vaccine candidateParticipants enrolled in the Sentinel Cohort received 0.5 mL RSV vaccine dose C2 as an IM injection on Day 1 of Stage 1.
Stage 1: Sentinel Cohort: Placebo	Placebo comparator	Other: PlaceboParticipants enrolled in the Sentinel Cohort received 0.5 mL placebo matched to RSV vaccine as an IM injection on Day 1 of Stage 1.
Stage 1: Main Cohort: RSV Vaccine Dose A1	Experimental	Biological: RSV vaccine candidateParticipants enrolled in the Main Cohort received 0.5 mL RSV vaccine dose A1 as an IM injection on Day 1 of Stage 1.
Stage 1: Main Cohort: RSV Vaccine Dose A2	Experimental	Biological: RSV vaccine candidateParticipants enrolled in the Main Cohort received 0.5 mL RSV vaccine dose A2 as an IM injection on Day 1 of Stage 1.
Stage 1: Main Cohort: RSV Vaccine Dose B1	Experimental	Biological: RSV vaccine candidateParticipants enrolled in the Main Cohort received 0.5 mL RSV vaccine dose B1 as an IM injection on Day 1 of Stage 1.
Stage 1: Main Cohort: RSV Vaccine Dose B2	Experimental	Biological: RSV vaccine candidateParticipants enrolled in the Main Cohort received 0.5 mL RSV vaccine dose B2 as an IM injection on Day 1 of Stage 1.
Stage 1: Main Cohort: RSV Vaccine Dose C1	Experimental	Biological: RSV vaccine candidateParticipants enrolled in the Main Cohort received 0.5 mL RSV vaccine dose C1 as an IM injection on Day 1 of Stage 1.
Stage 1: Main Cohort: RSV Vaccine Dose C2	Experimental	Biological: RSV vaccine candidateParticipants enrolled in the Main Cohort received 0.5 mL RSV vaccine dose C2 as an IM injection on Day 1 of Stage 1.
Stage 1: Main Cohort: Placebo	Placebo comparator	Other: PlaceboParticipants enrolled in the Main Cohort received 0.5 mL placebo matched to RSV vaccine as an IM injection on Day 1 of Stage 1.
Stage 2: RSV Vaccine Dose C2	Experimental	Biological: RSV vaccine candidateParticipants received 0.5 mL RSV vaccine dose C2 as an IM injection on Day 1 of Stage 2.
Stage 2: RSV Vaccine Dose D	Experimental	Biological: RSV vaccine candidateParticipants received 0.5 mL RSV vaccine dose D as an IM injection on Day 1 of Stage 2.
Stage 2: Placebo	Placebo comparator	Other: PlaceboParticipants received 0.5 mL placebo matched to RSV vaccine as an IM injection on Day 1 of Stage 2.

Who may qualify

Ages: 18 years and older
Sex: All
Healthy volunteers: Accepted
Age groups: Adult, Older adult

Key inclusion criteria (10 listed)

Sentinel Cohort Stage 1: Aged 18 to 50 years on the day of inclusion
Main Cohort Stage 1 and Stage 2: Aged 60 years or older on the day of inclusion
Sentinel Cohort: A female participant was eligible to participate if she was not pregnant or breastfeeding and:
Main and Booster Cohorts: A female participant was eligible to participate if she was not pregnant or breastfeeding and:
Able to attend all scheduled visits and to comply with all study procedures

Key exclusion criteria (15 listed)

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, 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
History of RSV-associated illness, diagnosed clinically, serologically, or microbiologically in the last 12 months
Previous history of myocarditis, pericarditis, and/or myopericarditis
Thrombocytopenia or bleeding disorder, contraindicating IM injection based on investigator's judgment

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
RSV vaccine candidatePharmaceutical Form: Liquid frozen solution in a vial Route of Administration: Intramuscular injection	Biological	Stage 1: Main Cohort: RSV Vaccine Dose A1, Stage 1: Main Cohort: RSV Vaccine Dose A2, Stage 1: Main Cohort: RSV Vaccine Dose B1, Stage 1: Main Cohort: RSV Vaccine Dose B2, Stage 1: Main Cohort: RSV Vaccine Dose C1, Stage 1: Main Cohort: RSV Vaccine Dose C2, Stage 1: Sentinel Cohort: RSV Vaccine Dose A1, Stage 1: Sentinel Cohort: RSV Vaccine Dose A2, Stage 1: Sentinel Cohort: RSV Vaccine Dose B1, Stage 1: Sentinel Cohort: RSV Vaccine Dose B2, Stage 1: Sentinel Cohort: RSV Vaccine Dose C1, Stage 1: Sentinel Cohort: RSV Vaccine Dose C2, Stage 2: RSV Vaccine Dose C2, Stage 2: RSV Vaccine Dose D
PlaceboPharmaceutical Form: Liquid Route of Administration: Intramuscular injection	Other	Stage 1: Main Cohort: Placebo, Stage 1: Sentinel Cohort: Placebo, Stage 2: Placebo

Primary outcome

Stage 1 (Sentinel and Main Cohort) and Stage 2: Number of Participants With Immediate Unsolicited Systemic Adverse Events (AEs)
Time frame: Up to 30 minutes post-primary vaccination on Day 1
An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study vaccine, whether or not considered related to the study vaccine. Immediate events were recorded to capture medically relevant unsolicited systemic AEs which occurred within the first 30 minutes after vaccination. An unsolicited AE was an observed AE that did not fulfill the conditions of solicited reactions, i.e., pre-listed in the case report form (CRF) in terms of diagnosis and onset window post-vaccination.
Stage 1 (Sentinel and Main Cohort) and Stage 2: Number of Participants With Solicited Injection Site Reactions and Systemic Reactions
Time frame: From Day 1 (first dose of primary vaccination) up to Day 8 (7 days post-primary vaccination on Day 1)
An injection site reaction was an adverse reaction (AR) at and around the injection site of the study vaccine. Injection site reactions were commonly inflammatory reactions. Solicited injection site reactions were reactions at and around the injection site of the study vaccine observed and reported under the conditions (nature and onset) pre-listed in the protocol and CRF. Solicited systemic reactions were systemic AEs observed and reported under the conditions (nature and onset) pre-listed in the protocol and CRF. Solicited reactions were considered to be related to the study vaccine administered.
Stage 1 (Sentinel and Main Cohort) and Stage 2: Number of Participants With Unsolicited Adverse Events
Time frame: From Day 1 (first dose of primary vaccination) up to Day 29 (28 days post-primary vaccination on Day 1)
An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study vaccine, whether or not considered related to the study vaccine. An unsolicited AE was an observed AE that did not fulfill the conditions of solicited reactions, i.e., pre-listed in the CRF in terms of diagnosis and onset window post-vaccination.
Stage 1 (Sentinel and Main Cohort): Number of Participants With Medically Attended Adverse Events (MAAEs)
Time frame: From Day 1 (first dose of primary vaccination) up to Day 29 (28 days post-primary vaccination on Day 1)
An MAAE was a new-onset or a worsening of a condition that prompted the participant to seek unplanned medical advice at a physician's office or Emergency Department.
Stage 2: Number of Participants With Medically Attended Adverse Events
Time frame: From Day 1 (first dose of primary vaccination) to Day 180
An MAAE was a new-onset or a worsening of a condition that prompted the participant to seek unplanned medical advice at a physician's office or Emergency Department.
Stage 1 (Sentinel and Main Cohort) and Stage 2: Number of Participants With Serious Adverse Events (SAEs) and Adverse Events of Special Interest (AESIs)
Time frame: From Day 1 (first dose of primary vaccination) to Day 365 (Stage 1 Sentinel and Main Cohorts); From Day 1 (first dose of primary vaccination) to Day 180 (Stage 2)
An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study vaccine, whether or not considered related to the study vaccine. An SAE was defined as any AE that at any dose resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, or was an important medical event. An AESI (serious or non-serious) was 1 of scientific and medical concern specific to the Sponsor's study vaccine or program, for which ongoing monitoring and rapid communication by the investigator to the Sponsor was appropriate.
Stage 1 (Sentinel and Main Cohort) and Stage 2: Number of Participants With Shifts From Baseline to Out-of-Range Biological Test Results
Time frame: From baseline (Day -14 to Day -1) up to Day 8 (7 days post-primary vaccination on Day 1)
Clinical evaluation of laboratory parameters (hematology, clinical chemistry and coagulation parameters) was performed to determine out-of-range values (below or above normal range). Number of participants with a shift from baseline to out-of-range value within 7 days after primary vaccination (Day 8) are reported. Laboratory parameters with a notable shift from baseline included: hematology: hemoglobin, white blood cells (WBC), red blood cells (RBC); clinical chemistry: blood urea nitrogen (BUN), potassium, glucose, C-reactive protein (CRP), direct bilirubin, troponin I; and coagulation parameters: partial thromboplastin time (PTT).
Stage 1 (Sentinel and Main Cohort): Geometric Mean Titers (GMTs) of Neutralizing Antibodies Against Respiratory Syncytial Virus A
Time frame: Day 1 (pre-primary vaccination) and Day 29 (28 days post-primary vaccination on Day 1)
Neutralizing antibodies activity against RSV A was measured using the RSV plaque reduction neutralization test (PRNT) (micro-PRNT). RSV A serum neutralizing antibodies titers were expressed as 1/dilution.
Stage 2: Geometric Mean Titers of Neutralizing Antibodies Against Respiratory Syncytial Virus A and Respiratory Syncytial Virus B
Time frame: Day 1 (pre-primary vaccination) and Day 29 (28 days post-primary vaccination on Day 1)
Neutralizing antibodies activity against RSV A and RSV B was measured using the RSV PRNT (micro-PRNT). RSV A and RSV B serum neutralizing antibodies titers were expressed as 1/dilution.

10 secondary outcomes

Stage 1 (Booster Cohort): Number of Participants With Immediate Unsolicited Systemic Adverse Events
Time frame: Up to 30 minutes post-booster vaccination at Month 12
Stage 1 (Booster Cohort): Number of Participants With Solicited Injection Site Reactions and Systemic Reactions
Time frame: Up to 7 days post-booster vaccination at Month 12
Stage 1 (Booster Cohort): Number of Participants With Unsolicited Adverse Events and Medically Attended Adverse Events
Time frame: Up to 28 days post-booster vaccination at Month 12
Stage 1 (Booster Cohort): Number of Participants With Serious Adverse Events and Adverse Events of Special Interest
Time frame: From Month 12 (first dose of booster vaccination) to Month 24
Stage 1 (Booster Cohort): Number of Participants With Shifts From Baseline to Out-of-Range Biological Test Results
Time frame: From baseline (Month 12: Day -14 to Day -1) up to 7 days post-booster vaccination at Month 12
Stage 1 (Sentinel and Main Cohort): Geometric Mean Titers of Neutralizing Antibodies Against Respiratory Syncytial Virus A
Time frame: 3, 6, and 12 months post-primary vaccination on Day 1
Stage 1 (Sentinel and Main Cohort): Geometric Mean Concentration of Binding Antibodies Against Respiratory Syncytial Virus Anti-F Immunoglobulin G (IgG)
Time frame: Day 1 (pre-primary vaccination), Day 29, and 3, 6, and 12 months post-primary vaccination on Day 1
Stage 1 (Booster Cohort): Geometric Mean Titers of Neutralizing Antibodies Against Respiratory Syncytial Virus A
Time frame: Month 12 (pre-booster vaccination), and 28 days (Month 13), 3 months (Month 15), 6 months (Month 18), and 12 months (Month 24) post-booster vaccination at Month 12
Stage 1 (Booster Cohort): Geometric Mean Concentration of Binding Antibodies Against Respiratory Syncytial Virus Anti-F Immunoglobulin G
Time frame: Month 12 (pre-booster vaccination), and 28 days (Month 13), 3 months (Month 15), 6 months (Month 18), and 12 months (Month 24) post-booster vaccination on Month 12
Stage 2: Geometric Mean Concentration of Binding Antibodies Against Respiratory Syncytial Virus Anti-F Immunoglobulin G
Time frame: Day 1 (pre-primary vaccination) and Day 29 (28 days post-primary vaccination on Day 1)

Results and safety

Results posted to the registry on 5 Aug 2026, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Stage 1: Sentinel Cohort: RSV Vaccine Dose A1	10	10
Stage 1: Sentinel Cohort: RSV Vaccine Dose A2	10	9
Stage 1: Sentinel Cohort: RSV Vaccine Dose B1	10	10
Stage 1: Sentinel Cohort: RSV Vaccine Dose B2	10	10
Stage 1: Sentinel Cohort: RSV Vaccine Dose C1	10	10
Stage 1: Sentinel Cohort: RSV Vaccine Dose C2	10	10
Stage 1: Sentinel Cohort: Placebo	30	29
Stage 1: Main Cohort: RSV Vaccine Dose A1	100	100
Stage 1: Main Cohort: RSV Vaccine Dose A2	101	101
Stage 1: Main Cohort: RSV Vaccine Dose B1	100	99
Stage 1: Main Cohort: RSV Vaccine Dose B2	100	100
Stage 1: Main Cohort: RSV Vaccine Dose C1	100	99
Stage 1: Main Cohort: RSV Vaccine Dose C2	100	97
Stage 1: Main Cohort: Placebo	99	98
Stage 1: Booster Cohort: RSV Vaccine Dose C2 at V01 and V08	0	0
Stage 1: Booster Cohort: RSV Vaccine Dose C2 at V01 and Placebo at V08	0	0
Stage 1: Booster Cohort: Placebo at V01 and RSV Vaccine Dose C2 at V08	0	0
Stage 1: Booster Cohort: Placebo at V01 and V08	0	0
Stage 2: RSV Vaccine Dose C2	0	0
Stage 2: RSV Vaccine Dose D	0	0
Stage 2: Placebo	0	0

Primary outcome: Stage 1 (Sentinel and Main Cohort) and Stage 2: Number of Participants With Immediate Unsolicited Systemic Adverse Events (AEs)

Time frame: Up to 30 minutes post-primary vaccination on Day 1. Count of participants. Unit: Participants

Measure	Stage 1: Sentinel Cohort: RSV Vaccine Dose A1 n = 10	Stage 1: Sentinel Cohort: RSV Vaccine Dose A2 n = 9	Stage 1: Sentinel Cohort: RSV Vaccine Dose B1 n = 10	Stage 1: Sentinel Cohort: RSV Vaccine Dose B2 n = 10	Stage 1: Sentinel Cohort: RSV Vaccine Dose C1 n = 10	Stage 1: Sentinel Cohort: RSV Vaccine Dose C2 n = 10	Stage 1: Sentinel Cohort: Placebo n = 30	Stage 1: Main Cohort: RSV Vaccine Dose A1 n = 100	Stage 1: Main Cohort: RSV Vaccine Dose A2 n = 101	Stage 1: Main Cohort: RSV Vaccine Dose B1 n = 100	Stage 1: Main Cohort: RSV Vaccine Dose B2 n = 100	Stage 1: Main Cohort: RSV Vaccine Dose C1 n = 100	Stage 1: Main Cohort: RSV Vaccine Dose C2 n = 98	Stage 1: Main Cohort: Placebo n = 99	Stage 2: RSV Vaccine Dose C2 n = 25	Stage 2: RSV Vaccine Dose D n = 24	Stage 2: Placebo n = 26
Value	0	0	0	0	0	0	0	0	0	0	0	1	1	0	0	0	0

Population analysed: Stage 1 (Sentinel and Main Cohort): Safety Analysis Set (SafAS) 1 included participants who received the study vaccine or placebo at Visit 01 (Day 1). Stage 2: SafAS3 included participants who received at least 1 injection of the study vaccine or placebo at Visit 01 (Day 1).

Primary outcome: Stage 1 (Sentinel and Main Cohort) and Stage 2: Number of Participants With Solicited Injection Site Reactions and Systemic Reactions

Time frame: From Day 1 (first dose of primary vaccination) up to Day 8 (7 days post-primary vaccination on Day 1). Count of participants. Unit: Participants

Measure	Stage 1: Sentinel Cohort: RSV Vaccine Dose A1 n = 10	Stage 1: Sentinel Cohort: RSV Vaccine Dose A2 n = 9	Stage 1: Sentinel Cohort: RSV Vaccine Dose B1 n = 10	Stage 1: Sentinel Cohort: RSV Vaccine Dose B2 n = 10	Stage 1: Sentinel Cohort: RSV Vaccine Dose C1 n = 10	Stage 1: Sentinel Cohort: RSV Vaccine Dose C2 n = 10	Stage 1: Sentinel Cohort: Placebo n = 29	Stage 1: Main Cohort: RSV Vaccine Dose A1 n = 100	Stage 1: Main Cohort: RSV Vaccine Dose A2 n = 101	Stage 1: Main Cohort: RSV Vaccine Dose B1 n = 100	Stage 1: Main Cohort: RSV Vaccine Dose B2 n = 100	Stage 1: Main Cohort: RSV Vaccine Dose C1 n = 100	Stage 1: Main Cohort: RSV Vaccine Dose C2 n = 98	Stage 1: Main Cohort: Placebo n = 99	Stage 2: RSV Vaccine Dose C2 n = 25	Stage 2: RSV Vaccine Dose D n = 24	Stage 2: Placebo n = 26
Solicited injection site reaction	4	2	5	5	7	7	3	40	29	54	57	72	53	9	17	18	3
Solicited systemic reaction	2	2	2	3	6	7	8	30	29	49	41	47	44	33	13	17	9

Primary outcome: Stage 1 (Sentinel and Main Cohort) and Stage 2: Number of Participants With Unsolicited Adverse Events

Time frame: From Day 1 (first dose of primary vaccination) up to Day 29 (28 days post-primary vaccination on Day 1). Count of participants. Unit: Participants

Measure	Stage 1: Sentinel Cohort: RSV Vaccine Dose A1 n = 10	Stage 1: Sentinel Cohort: RSV Vaccine Dose A2 n = 9	Stage 1: Sentinel Cohort: RSV Vaccine Dose B1 n = 10	Stage 1: Sentinel Cohort: RSV Vaccine Dose B2 n = 10	Stage 1: Sentinel Cohort: RSV Vaccine Dose C1 n = 10	Stage 1: Sentinel Cohort: RSV Vaccine Dose C2 n = 10	Stage 1: Sentinel Cohort: Placebo n = 30	Stage 1: Main Cohort: RSV Vaccine Dose A1 n = 100	Stage 1: Main Cohort: RSV Vaccine Dose A2 n = 101	Stage 1: Main Cohort: RSV Vaccine Dose B1 n = 100	Stage 1: Main Cohort: RSV Vaccine Dose B2 n = 100	Stage 1: Main Cohort: RSV Vaccine Dose C1 n = 100	Stage 1: Main Cohort: RSV Vaccine Dose C2 n = 98	Stage 1: Main Cohort: Placebo n = 99	Stage 2: RSV Vaccine Dose C2 n = 25	Stage 2: RSV Vaccine Dose D n = 24	Stage 2: Placebo n = 26
Value	0	0	1	0	4	1	2	27	24	31	27	27	22	22	6	11	6

Population analysed: Stage 1 (Sentinel and Main Cohort): SafAS1 included participants who received the study vaccine or placebo at Visit 01 (Day 1). Stage 2: SafAS3 included participants who received at least 1 injection of the study vaccine or placebo at Visit 01 (Day 1).

Primary outcome: Stage 1 (Sentinel and Main Cohort): Number of Participants With Medically Attended Adverse Events (MAAEs)

Time frame: From Day 1 (first dose of primary vaccination) up to Day 29 (28 days post-primary vaccination on Day 1). Count of participants. Unit: Participants

Measure	Stage 1: Sentinel Cohort: RSV Vaccine Dose A1 n = 10	Stage 1: Sentinel Cohort: RSV Vaccine Dose A2 n = 9	Stage 1: Sentinel Cohort: RSV Vaccine Dose B1 n = 10	Stage 1: Sentinel Cohort: RSV Vaccine Dose B2 n = 10	Stage 1: Sentinel Cohort: RSV Vaccine Dose C1 n = 10	Stage 1: Sentinel Cohort: RSV Vaccine Dose C2 n = 10	Stage 1: Sentinel Cohort: Placebo n = 30	Stage 1: Main Cohort: RSV Vaccine Dose A1 n = 100	Stage 1: Main Cohort: RSV Vaccine Dose A2 n = 101	Stage 1: Main Cohort: RSV Vaccine Dose B1 n = 100	Stage 1: Main Cohort: RSV Vaccine Dose B2 n = 100	Stage 1: Main Cohort: RSV Vaccine Dose C1 n = 100	Stage 1: Main Cohort: RSV Vaccine Dose C2 n = 98	Stage 1: Main Cohort: Placebo n = 99
Value	0	0	0	0	1	1	0	4	5	4	3	3	2	6

Population analysed: SafAS 1 included participants who received the study vaccine or placebo at Visit 01 (Day 1).

10 secondary outcomes are reported in the full results.

Adverse events

Time frame: AEs and deaths were collected from Day 1 (first dose of primary vaccination) to Day 365 (Stage 1 Sentinel and Main Cohort); from Month 12 (first dose of booster vaccination) to Month 24 (Stage 1 Booster Cohort); from Day 1 (first dose of primary vaccination) to Day 180 (Stage 2).. Other adverse events reported at 5% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Stage 1: Sentinel Cohort: RSV Vaccine Dose A1	0 of 10 (0%)	5 of 10 (50%)	0 of 10
Stage 1: Sentinel Cohort: RSV Vaccine Dose A2	0 of 9 (0%)	2 of 9 (22.2%)	0 of 9
Stage 1: Sentinel Cohort: RSV Vaccine Dose B1	0 of 10 (0%)	5 of 10 (50%)	0 of 10
Stage 1: Sentinel Cohort: RSV Vaccine Dose B2	0 of 10 (0%)	6 of 10 (60%)	0 of 10
Stage 1: Sentinel Cohort: RSV Vaccine Dose C1	1 of 10 (10%)	8 of 10 (80%)	0 of 10
Stage 1: Sentinel Cohort: RSV Vaccine Dose C2	0 of 10 (0%)	8 of 10 (80%)	0 of 10
Stage 1: Sentinel Cohort: Placebo	0 of 30 (0%)	8 of 30 (26.7%)	0 of 30
Stage 1: Main Cohort: RSV Vaccine Dose A1	10 of 100 (10%)	54 of 100 (54%)	0 of 100
Stage 1: Main Cohort: RSV Vaccine Dose A2	4 of 101 (4%)	47 of 101 (46.5%)	0 of 101
Stage 1: Main Cohort: RSV Vaccine Dose B1	8 of 100 (8%)	72 of 100 (72%)	1 of 100
Stage 1: Main Cohort: RSV Vaccine Dose B2	6 of 100 (6%)	74 of 100 (74%)	0 of 100
Stage 1: Main Cohort: RSV Vaccine Dose C1	3 of 100 (3%)	76 of 100 (76%)	0 of 100
Stage 1: Main Cohort: RSV Vaccine Dose C2	7 of 98 (7.1%)	63 of 98 (64.3%)	0 of 98
Stage 1: Main Cohort: Placebo	8 of 99 (8.1%)	38 of 99 (38.4%)	1 of 99
Stage 1: Booster Cohort: RSV Vaccine Dose C2 at V01 and V08	3 of 31 (9.7%)	24 of 31 (77.4%)	1 of 31
Stage 1: Booster Cohort: RSV Vaccine Dose C2 at V01 and Placebo at V08

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 5 Aug 2026.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
VAE00010 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

33 sites in 3 countries: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 1/2 study testing RSV vaccine candidate in people with Respiratory Syncytial Virus Immunization, run by Sanofi Pasteur, a Sanofi Company at 33 sites in 3 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 10 inclusion and 15 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 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 33 sites in United States, Puerto Rico, 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. Some participants in this study may receive a placebo. 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?

Yes. Results are posted in the registry (first posted 5 Aug 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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?

Stage 1 (Sentinel and Main Cohort) and Stage 2: Number of Participants With Immediate Unsolicited Systemic Adverse Events (AEs) (time frame: Up to 30 minutes post-primary vaccination on Day 1). The study lists 9 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 NCT05639894.

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 Aug 2026.