mRNA Vaccine for Respiratory Syncytial Virus

No longer recruiting at 25 trial locations

Overseen By Trial Transparency email recommended (Toll free for US & Canada)

Age: 18+

Sex: Any

Trial Phase: Phase 1

Sponsor: Sanofi Pasteur, a Sanofi Company

Disqualifiers: Any interfering condition, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 30

Duration: 1 day

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to test the safety and effectiveness of a new mRNA vaccine to prevent lung infections caused by RSV and hMPV in older adults. Participants will receive a single shot of the vaccine, with different groups receiving varying doses and formulations to determine the most effective option. Ideal participants are healthy individuals who have experienced lung-related issues, such as frequent coughs or breathing difficulties, and are either between 18 to 49 years or 60 years and older. As a Phase 1 trial, participants will be among the first to receive this new treatment, aiding researchers in understanding its effects in people.

Do I need to stop my current medications to join the trial?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial team or your doctor.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that mRNA vaccines for respiratory viruses like RSV and hMPV are generally safe and well-tolerated. Studies on similar mRNA vaccines have found that most people do not experience serious side effects. Specifically, an mRNA vaccine for hMPV was well-received, with participants showing strong immune responses.

For the RSV mRNA vaccine, safety data indicate that these vaccines are safe for humans. The mRNA used is not from a virus, so it cannot cause the disease. Approved mRNA vaccines for RSV have been very effective in preventing many RSV-related illnesses.

Since this trial is in its early stages, the main focus is on ensuring the vaccine's safety in humans. Researchers are still collecting data, but past studies on similar vaccines provide a reassuring picture of their safety. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatments?

Researchers are excited about these mRNA vaccines for Respiratory Syncytial Virus (RSV) and Human Metapneumovirus (hMPV) because they represent a cutting-edge approach to preventing these infections. Unlike traditional vaccines that use weakened or inactivated viruses, these investigational vaccines use mRNA technology to instruct cells to produce viral proteins, triggering an immune response. This method can potentially offer quicker development and adaptability to emerging viral strains. Additionally, the use of lipid nanoparticles (LNPs) for delivery is designed to enhance stability and ensure efficient delivery of the mRNA into cells, potentially boosting the vaccine's effectiveness.

What evidence suggests that this trial's treatments could be effective for preventing lower respiratory tract disease caused by RSV and hMPV?

Studies have shown promising results for mRNA vaccines targeting respiratory illnesses. In this trial, participants will receive different versions of mRNA vaccines targeting RSV and hMPV. Research has demonstrated that vaccines aimed at RSV work very well, with some versions preventing over 83.7% of RSV-related illnesses. The RSV mRNA vaccine uses tiny carriers called lipid nanoparticles to deliver the vaccine and has elicited strong immune responses in older adults. Meanwhile, vaccines for human metapneumovirus (hMPV) have significantly boosted the body's defenses against the virus. These findings suggest that mRNA vaccines could potentially prevent infections caused by RSV and hMPV in older adults. ^{3 4 5 6 7}

Are You a Good Fit for This Trial?

This trial is for healthy adults aged 18-49 and those 60 or older. Participants must have signed a consent form. They can't join if they have any health issues that might affect the study's results, as judged by the study leader.

Inclusion Criteria

Informed consent form (ICF) has been signed and dated

Exclusion Criteria

Any condition which, in the opinion of the Investigator, might interfere with the evaluation of the study objectives

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive a single intramuscular injection of the RSV/hMPV mRNA vaccine candidate at various doses

1 day

1 visit (in-person)

Follow-up

Participants are monitored for safety and immunogenicity, including serum neutralizing antibody titers and adverse events

6 months

Multiple visits (in-person and virtual) at Day 29, Day 91, and Day 181

What Are the Treatments Tested in This Trial?

Interventions

• hMPV mRNA LNP 1
• RSV/hMPV mRNA LNP 1
• RSV/hMPV mRNA LNP 2
• RSV mRNA LNP 1

Trial Overview The trial tests an experimental mRNA vaccine designed to prevent lung infections caused by two viruses: RSV and hMPV. Participants will receive one intramuscular injection of various doses of this vaccine in different formulations.

How Is the Trial Designed?

Group I: hMPV mRNA / LNP 1 Group 6 Experimental Treatment 1 Intervention

Participants will be randomized to receive a single IM injection of hMPV mRNA / LNP vaccine 1 dose 1.

Group II: RSV/hMPV mRNA / LNP 2 Group 4 Experimental Treatment 1 Intervention

Participants will be randomized to receive a single IM injection of RSV/hMPV mRNA / LNP vaccine 2 dose 1.

Group III: RSV/hMPV mRNA / LNP 1 Group 7 Experimental Treatment 1 Intervention

Participants will be randomized to receive a single IM injection of RSV/hMPV mRNA / LNP vaccine 1 dose 4.

Group IV: RSV/hMPV mRNA / LNP 1 Group 3 Experimental Treatment 1 Intervention

Participants will be randomized to receive a single IM injection of RSV/hMPV mRNA / LNP vaccine 1 dose 3.

Group V: RSV/hMPV mRNA / LNP 1 Group 2 Experimental Treatment 1 Intervention

Participants will be randomized to receive a single IM injection of RSV/hMPV mRNA / LNP vaccine 1 dose 2.

Group VI: RSV/hMPV mRNA / LNP 1 Group 1 Experimental Treatment 1 Intervention

Participants will be randomized to receive a single IM injection of RSV/hMPV mRNA / LNP vaccine 1 dose 1.

Group VII: RSV mRNA / LNP 1 Group 5 Experimental Treatment 1 Intervention

Participants will be randomized to receive a single IM injection of RSV mRNA / LNP vaccine 1 dose 1.

Who Is Running the Clinical Trial?

Sanofi Pasteur, a Sanofi Company

Lead Sponsor

Trials

429

Recruited

6,140,000+

Paul Hudson

Sanofi Pasteur, a Sanofi Company

Chief Executive Officer since 2019

Degree in Economics from Manchester Metropolitan University

Dr. Thomas Triomphe

Sanofi Pasteur, a Sanofi Company

Chief Medical Officer since 2020

MD from Tehran University of Medical Sciences

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC12197462/

Highly Effective mRNA-LNP Vaccine Against Respiratory ... Here, we designed an effective RSV mRNA vaccine, STR-V003, consisting of mRNA encoding preF protein in lipid nanoparticles (LNPs).

2. nature.com nature.com/articles/s41541-025-01205-x

Improved mRNA-based RSV vaccine with PreF forming ... The currently approved RSV mRNA vaccines, encoding the PreF protein of RSV have exhibited high efficacy, preventing over 83.7% of RSV-related ...

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC11724408/

The recent landscape of RSV vaccine research - PMC Recent advancements include nirsevimab, a long-acting mAb that has shown substantial efficacy in reducing medically attended RSV-related disease in infants.

4. academic.oup.com academic.oup.com/jid/article/230/3/e647/7612559

Safety and Immunogenicity of an mRNA-Based RSV Vaccine ... An mRNA-based respiratory syncytial virus (RSV) vaccine, mRNA-1345, is under clinical investigation to address RSV disease burden in older adults.

5. journals.asm.org journals.asm.org/doi/10.1128/jvi.01209-25

Developing an eVLP mRNA vaccine for respiratory syncytial ... Overall, these findings demonstrate that the Pre-F-EABR mRNA vaccine induces more robust immune responses, highlighting its potential in ...

6. medicomart.com medicomart.com/images/document/RSV%20SDS%20sheet.pdf

Safety Data Sheet The mRNA in the RSV vaccine is not viral or pathogenic and does not require specific biosafety handling recommendations.

7. cdc.gov cdc.gov/vaccine-safety/vaccines/rsv.html

Respiratory Syncytial Virus (RSV) Vaccine Safety RSV immunizations protect people at increased risk for severe RSV disease when used according to the approved guidelines and recommendations.