Study to Evaluate the Safety and Immunogenicity of Investigational Vaccines Using the RSV (Respiratory Syncytial Virus) Monovalent Antigen in Healthy Participants 18 to 49 Years of Age

NCT07071558 | Completed Phase 1

• 2 other identifiers: VAV00026WHO UTN
• Study Type: interventional
• Target: 240
• Locations: 1 country
• Sites: 6

Brief Summary

The purpose of this study is to evaluate the safety and immunogenicity of different liponanaoparticle (LNP) formulations of modified ribonucleic acid (mRNA) vaccines using the RSV pre-F antigen in healthy participants 18 to 49 years of age.

• Each participant will remain in the study for approximately 6 months.
• The study intervention will be administered as a single intramuscular (IM) dose in the upper arm on Day 1 (D01).
• The visit frequency will include 1 Screening Visit, 4 planned site visits to occur on D01, D03, D08, and D29, and 2 telephone calls to occur at Month (M)3 and M6.

Conditions

Respiratory Syncytial Virus Immunization

Keywords

RSV; RSV Infection; RSV Vaccine

Outcome Measures

Primary Outcomes (7)

• Presence of any unsolicited systemic adverse events (aes)

  Number of participants experiencing immediate AEs

  Within 30 minutes after each vaccine injection

• Presence of solicited injection site reactions (ie, pre-listed in the participant's diary and in the eCRF (electronic case report form)

  Number of participants experiencing solicited injection site reactions

  Through 7 days after each vaccine injection

• Presence of solicited systemic reactions (ie, pre-listed in the participant diary and in the CRF)

  Number of participants experiencing solicited systemic reactions

  Through 7 days after each vaccine injection

• Presence of unsolicited AEs

  Number of participants experiencing unsolicited AEs

  Day 1 through day 29

• Presence of SAEs (Serious Adverse Events) and AESIs (Adverse Events of Special Interest)

  Number of participants experiencing SAEs and AESIs

  Throughout study, approximately 6 months

• Presence of out-of-range biological test results (including shift from baseline values)

  number of participants with out-of-range biological tests

  Through 7 days after each vaccine injection

• RSV A nAb (Neutralizing Antibodies) titers

  At day 1 and day 29

Study Arms (8)

RSV Formulation 1

EXPERIMENTAL

Participants will receive a single IM (Intramuscular) injection on day 1 of the RSV vaccines according to their randomization schedule.

Biological: RSV vaccine formulation 1 dose

RSV Formulation 2

EXPERIMENTAL

Participants will receive a single IM (Intramuscular) injection on day 1 of the RSV vaccines according to their randomization schedule.

Biological: RSV vaccine formulation 2 dose

RSV Formulation 3

EXPERIMENTAL

Participants will receive a single IM (Intramuscular) injection on day 1 of the RSV vaccines according to their randomization schedule.

Biological: RSV vaccine formulation 3 dose

RSV Formulation 4

EXPERIMENTAL

Participants will receive a single IM (Intramuscular) injection on day 1 of the RSV vaccines according to their randomization schedule.

Biological: RSV vaccine formulation 4 dose

RSV Formulation 5

EXPERIMENTAL

Participants will receive a single IM (Intramuscular) injection on day 1 of the RSV vaccines according to their randomization schedule.

Biological: RSV vaccine formulation 5 dose

RSV Formulation 6

EXPERIMENTAL

Participants will receive a single IM (Intramuscular) injection on day 1 of the RSV vaccines according to their randomization schedule.

Biological: RSV vaccine formulation 6 dose

Control group 1 dose 1

EXPERIMENTAL

Participants will receive a single IM (Intramuscular) injection on day 1 of the RSV vaccines according to their randomization schedule.

Biological: RSV vaccine formulation 7 dose

Control group 2 dose 2

EXPERIMENTAL

Participants will receive a single IM (Intramuscular) injection on day 1 of the RSV vaccines according to their randomization schedule.

Biological: RSV vaccine formulation 8 dose

Interventions

RSV vaccine formulation 1 dose BIOLOGICAL

Suspension for injection. Route of administration: IM injection

RSV Formulation 1

RSV vaccine formulation 2 dose BIOLOGICAL

Suspension for injection. Route of administration: IM injection

RSV Formulation 2

RSV vaccine formulation 3 dose BIOLOGICAL

Suspension for injection. Route of administration: IM injection

RSV Formulation 3

RSV vaccine formulation 4 dose BIOLOGICAL

Suspension for injection. Route of administration: IM injection

RSV Formulation 4

RSV vaccine formulation 5 dose BIOLOGICAL

Suspension for injection. Route of administration: IM injection

RSV Formulation 5

RSV vaccine formulation 6 dose BIOLOGICAL

Suspension for injection. Route of administration: IM injection

RSV Formulation 6

RSV vaccine formulation 7 dose BIOLOGICAL

Suspension for injection. Route of administration: IM injection

Control group 1 dose 1

RSV vaccine formulation 8 dose BIOLOGICAL

Suspension for injection. Route of administration: IM injection

Control group 2 dose 2

Eligibility Criteria

• Age: 18 Years - 49 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• A female participant is eligible to participate if she is not pregnant or breastfeeding and of the following conditions applies:
• Is of NCBP (Non-Child-Bearing Potential). To be considered of NCBP, a female must be post-menopausal for at least 1 year, or surgically sterile. OR
• Is of CBP (Child-Bearing Potential) and 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.

You may not qualify if:

• Any condition which, in the opinion of the Investigator, might interfere with the evaluation of the study objectives
• The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.

Sponsors & Collaborators

• Sanofi: lead

Study Sites (6)

Site # 0361003

Wollongong, New South Wales, 2500, Australia

Location

Site # 0361006

Brisbane, Queensland, 4006, Australia

Location

Site # 0361005

Morayfield, Queensland, 4506, Australia

Location

Site # 0361004

Southport, Queensland, 4215, Australia

Location

Site # 0361002

Bayswater, Victoria, 3153, Australia

Location

Site # 0361001

Camberwell, Victoria, 3124, Australia

Location

Related Links

• Plain Language Results Summary

MeSH Terms

Conditions

Respiratory Syncytial Virus Infections

Condition Hierarchy (Ancestors)

Pneumovirus Infections; Paramyxoviridae Infections; Mononegavirales Infections; RNA Virus Infections; Virus Diseases; Infections

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR
• Masking Details: Investigators, study site staff, laboratory personnel, outcome assessors, and participants will be blinded throughout the study. Study staff preparing and administering the study interventions will be unblinded throughout the study.
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 8, 2025
• First Posted: July 17, 2025
• Study Start: July 14, 2025
• Primary Completion: March 17, 2026
• Study Completion: March 17, 2026
• Last Updated: April 28, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP

Locations

AU (6)