A Phase 1 interventional study of RSV vaccine formulation 1 dose and RSV vaccine formulation 2 dose in Respiratory Syncytial Virus Immunization, sponsored by Sanofi. Completed at 6 sites in Australia. Open to participants aged 18 Years to 49 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-04-28.
Sponsored by Sanofi · Phase 1, Interventional, and Prevention
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.
293 studies on the registry are indexed under Respiratory Syncytial Virus Infections; 45 are open to participants now.
This study's enrollment of 240 is above the median of 90 across 213 interventional studies indexed under Respiratory Syncytial Virus Infections.
Browse Respiratory Syncytial Virus Infections studies →Sanofi is the lead sponsor of 1,508 studies on the registry; 90 are open to participants now.
Of its 198 completed or terminated interventional studies of FDA-regulated products, 118 (60%) have results posted.
Counted across the registry records on this site, refreshed daily.
A female participant is eligible to participate if she is not pregnant or breastfeeding and of the following conditions applies:
Exclusion Criteria:
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
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
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
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
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
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
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
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
Suspension for injection. Route of administration: IM injection
Suspension for injection. Route of administration: IM injection
Suspension for injection. Route of administration: IM injection
Suspension for injection. Route of administration: IM injection
Suspension for injection. Route of administration: IM injection
Suspension for injection. Route of administration: IM injection
Suspension for injection. Route of administration: IM injection
Suspension for injection. Route of administration: IM injection
Presence of any unsolicited systemic adverse events (aes)
Number of participants experiencing immediate AEs
Time frame: 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
Time frame: 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
Time frame: Through 7 days after each vaccine injection
Presence of unsolicited AEs
Number of participants experiencing unsolicited AEs
Time frame: 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
Time frame: 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
Time frame: Through 7 days after each vaccine injection
RSV A nAb (Neutralizing Antibodies) titers
Time frame: At day 1 and day 29
Plan to share: 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
Supporting information: Study protocol, Sap
This study is completed, as verified in Apr 2026. You cannot join it, but the record below documents what was studied.
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Respiratory Syncytial Virus Infections→
Sanofi