A Study of mRNA-1345 Vaccine Targeting Respiratory Syncytial Virus (RSV) in Adults ≥50 Years of Age

Study at a glance

From the registry record, last updated by the sponsor on 30 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title

A Phase 3 Randomized, Observer-Blind, Study to Evaluate Safety, Tolerability, and Immunogenicity of mRNA-1345, an mRNA Vaccine Targeting Respiratory Syncytial Virus (RSV), When Given Alone or Coadministered With a Seasonal Influenza Vaccine or SARS-CoV-2 Vaccine and When Given as an Open-label Boost at 1 Year Following a Primary Dose in Adults ≥ 50 Years of Age

ClinicalTrials.gov ID

NCT05330975

Acronym / sponsor ID

RSVictory / mRNA-1345-P302

Conditions

Respiratory Syncytial Virus

Keywords

Viral Diseases, Messenger RNA, Moderna, mRNA-1345, Respiratory syncytial virus, Safety, Vaccines, SARS-CoV-2

Phase

Phase 3

Study type

Interventional

Recruitment status

Completed

Enrolment

3,317 participants (actual)

Lead sponsor

ModernaTX, Inc.Industry (pharma, biotech, devices)

Study start

1 Apr 2022 (actual)

Primary completion

8 Nov 2024 (actual)

Study completion

8 Nov 2024 (actual)

First posted

15 Apr 2022 (actual)

Results

Posted 30 Dec 2025

Clinical summary

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

Study design

Primary purpose

Prevention

Allocation

Randomised

Intervention model

Parallel groups

Masking

Quadruple blind (participant, care provider, investigator, outcomes assessor)

Number of arms

7

Who may qualify

Ages

50 years and older

Sex

All

Healthy volunteers

Accepted

Age groups

Adult, Older adult

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Primary outcome

1. Part A: Number of Participants With Solicited Local and Systemic Adverse Reactions (ARs) Within 7 Days After Day 1 Injection

   Time frame: Within 7 days after Day 1 injection

   Solicited ARs were collected in an electronic diary (eDiary). Local ARs: injection site pain, erythema (redness), swelling/induration (hardness); and axillary (underarm) swelling or tenderness ipsilateral to the side of injection. Systemic ARs: fever, headache, fatigue, myalgia, arthralgia, nausea/vomiting, and chills. Note, not all solicited ARs were considered adverse events (AEs). Investigator reviewed whether the solicited AR was also to be recorded as an AE. A Summary of serious AEs (SAEs) and nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.

2. Part A: Number of Participants With Unsolicited Adverse Events (AEs) After Day 1 Injection

   Time frame: Day 1 through Day 28 (28 days after Day 1 injection)

   An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related. Any abnormal laboratory test result (hematology, clinical chemistry, or prothrombin time [PT]/partial thromboplastin time [PTT]) or other safety assessment (for example, electrocardiogram, radiological scan, vital sign measurement), including one that worsened from baseline and was considered clinically significant in the medical and scientific judgment of the Investigator was recorded as an AE. A summary of SAEs and all nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.

3. Part A: Number of Participants With Medically Attended AEs (MAAEs), SAEs, Adverse Events of Special Interest (AESIs), and AEs Leading to Withdrawal

   Time frame: Day 1 through Day 181 (end of Study Part A)

   A MAAE is an AE that leads to an unscheduled visit to a healthcare practitioner. An AESI is an AE (serious or nonserious) of scientific and medical concern specific to the Sponsor's product or program, for which ongoing monitoring and immediate notification by the Investigator to the Sponsor are required. An SAE was defined as any AE that resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in disability, was a congenital anomaly/birth defect, or was an important medical event. A summary of SAEs and all nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.

4. Part A: Geometric Mean Titer (GMT) of Serum Respiratory Syncytial Virus Subtype A (RSV-A) Neutralizing Antibodies (NAbs) at Day 29

   Time frame: Day 29

   Antibody values reported as below lower limit of quantification (LLOQ) were replaced by 0.5*LLOQ. Values greater than the upper limit of quantification (ULOQ) were replaced by the ULOQ. LLOQ was 13 international units (IU)/milliliter (mL) and ULOQ was 259061 IU/mL for RSV-A. As prespecified, only arms where participants received mRNA-1345 are presented for this outcome measure.

5. Part A: Percentage of Participants With Seroresponse in RSV-A NAbs at Day 29

   Time frame: Day 29

   Seroresponse was defined as ≥4 × lower limit of quantification (LLOQ) if baseline was <LLOQ or 4-fold or greater increase from baseline if baseline was ≥LLOQ. As prespecified, only arms where participants received mRNA-1345 are presented for this outcome measure.

6. Part A: GMT of Serum Anti-hemagglutination (HA) Ab Level, as Measured by Hemagglutination Inhibition (HAI) Assay for Influenza at Day 29

   Time frame: Day 29

   Influenza A strains included H1N1 and H3N2 and influenza B strains included Washington and Phuket strains. Antibody values reported as below LLOQ were replaced by 0.5*LLOQ. Values greater than the ULOQ were replaced by the ULOQ. LLOQ was 10 and ULOQ was 2560 for Influenza A. LLOQ was 10 and ULOQ was 640 for Influenza B. As prespecified, only arms where participants received Afluria® Quadrivalent are presented for this outcome measure.

7. Part B: Number of Participants With Solicited Local and Systemic ARs Within 7 Days After Day 1 Injection

   Time frame: Within 7 days after Day 1 injection

   Solicited ARs were collected in an eDiary. Local ARs: injection site pain, erythema (redness), swelling/induration (hardness); and axillary (underarm) swelling or tenderness ipsilateral to the side of injection. Systemic ARs: fever, headache, fatigue, myalgia, arthralgia, nausea/vomiting, and chills. Note, not all solicited ARs were considered AEs. Investigator reviewed whether the solicited AR was also to be recorded as an AE. A Summary of SAEs and nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.

8. Part B: Number of Participants With Solicited Local and Systemic ARs Within 7 Days After Day 29 Injection

   Time frame: Within 7 days after Day 29 injection

   Solicited ARs were collected in an eDiary. Local ARs: injection site pain, erythema (redness), swelling/induration (hardness); and axillary (underarm) swelling or tenderness ipsilateral to the side of injection. Systemic ARs: fever, headache, fatigue, myalgia, arthralgia, nausea/vomiting, and chills. Note, not all solicited ARs were considered AEs. Investigator reviewed whether the solicited AR was also to be recorded as an AE. A Summary of SAEs and nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.

9. Part B: Number of Participants With Unsolicited AEs After Day 1 Injection

   Time frame: Day 1 through Day 28 (28 days after Day 1 injection)

   An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related. Any abnormal laboratory test result (hematology, clinical chemistry, or PT/PTT) or other safety assessment (for example, electrocardiogram, radiological scan, vital sign measurement), including one that worsened from baseline and was considered clinically significant in the medical and scientific judgment of the Investigator was recorded as an AE. A summary of SAEs and all nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.

10. Part B: Number of Participants With Unsolicited AEs After Day 29 Injection

    Time frame: Day 29 through Day 57 (28 days after Day 29 injection)

    An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related. Any abnormal laboratory test result (hematology, clinical chemistry, or prothrombin time [PT]/partial thromboplastin time [PTT]) or other safety assessment (for example, electrocardiogram, radiological scan, vital sign measurement), including one that worsened from baseline and was considered clinically significant in the medical and scientific judgment of the Investigator was recorded as an AE. A summary of SAEs and all nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.

11. Part B: Number of Participants With MAAEs, SAEs, AESIs, and AEs Leading to Withdrawal

    Time frame: Day 1 through Day 211

    A MAAE is an AE that leads to an unscheduled visit to a healthcare practitioner. An AESI is an AE (serious or nonserious) of scientific and medical concern specific to the Sponsor's product or program, for which ongoing monitoring and immediate notification by the Investigator to the Sponsor are required. An SAE was defined as any AE that resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in disability, was a congenital anomaly/birth defect, or was an important medical event. A summary of SAEs and all nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.

12. Part B: GMT of Serum RSV-A at Day 29

    Time frame: Day 29

    Antibody values reported as below LLOQ were replaced by 0.5*LLOQ. Values greater than the upper limit of quantification (ULOQ) were replaced by the ULOQ. LLOQ was 13 IU/mL and ULOQ was 259061 IU/mL for RSV-A. As prespecified, only arms where participants received mRNA-1345 are presented for this outcome measure.

13. Part B: Percentage of Participants With Seroresponse for RSV-A Neutralizing Abs From Baseline to Day 29

    Time frame: Baseline to Day 29

    Seroresponse was defined as ≥4 × LLOQ if baseline was <LLOQ or 4-fold or greater increase from baseline if baseline was ≥LLOQ. As prespecified, only arms where participants received mRNA-1345 are presented for this outcome measure.

14. Part B: Geometric Mean Concentration (GMC) of Serum Ab Level, as Measured by Neutralization Assay for SARS-Cov-2 at Day 29

    Time frame: Day 29

    The model-based GM titer was estimated on ANCOVA model. SARS-CoV-2 variants included Wuhan-Hu-1 and B.1.1.529. Antibody values reported as below LLOQ were replaced by 0.5*LLOQ. Values greater than the ULOQ were replaced by the ULOQ. LLOQ was 10 arbitrary units (AU)/milliliters (mL) and ULOQ was 111433 AU/mL for Wuhan-Hu-1. LLOQ was 8 and ULOQ was B.1.1.529 for B1.1.529. As prespecified, only arms where participants received mRNA-1273.214 are presented for this outcome measure.

15. Part B: Percentage of Participants With Seroresponse for SARS-Cov-2 NAbs From Baseline to Day 29

    Time frame: Baseline to Day 29

    Seroresponse was defined as ≥4 × LLOQ if baseline was <LLOQ or 4-fold or greater increase from baseline if baseline was ≥LLOQ. mRNA-As prespecified, only arms where participants received mRNA-1273.214 are presented for this outcome measure.

16. Part C: Number of Participants With Solicited Local and Systemic Within 7 Days After Revaccination Day 1

    Time frame: Within 7 days after Day 1 revaccination

    Solicited ARs were collected in an electronic eDiary. Local ARs: injection site pain, erythema (redness), swelling/induration (hardness); and axillary (underarm) swelling or tenderness ipsilateral to the side of injection. Systemic ARs: fever, headache, fatigue, myalgia, arthralgia, nausea/vomiting, and chills. Note, not all solicited ARs were considered AEs. Investigator reviewed whether the solicited AR was also to be recorded as an AE. A Summary of SAEs and nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.

17. Part C: Number of Participants With Unsolicited AEs Within 28 Days After Revaccination Day 1

    Time frame: Revaccination Day 1 through Day 28 (28 days after revaccination Day 1)

    An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related. Any abnormal laboratory test result (hematology, clinical chemistry, or PT/PTT) or other safety assessment (for example, electrocardiogram, radiological scan, vital sign measurement), including one that worsened from baseline and was considered clinically significant in the medical and scientific judgment of the Investigator was recorded as an AE. A summary of SAEs and all nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.

18. Part C: Number of Participants With MAAEs

    Time frame: Revaccination Day 1 through Day 181

    A MAAE is an AE that leads to an unscheduled visit to a healthcare practitioner.

19. Part C: Number of Participants With SAEs, AESIs, and AEs Leading to Withdrawal

    Time frame: Revaccination Day 1 through Day 361

    An SAE was defined as any AE that resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in disability, was a congenital anomaly/birth defect, or was an important medical event. An AESI is an AE (serious or nonserious) of scientific and medical concern specific to the Sponsor's product or program, for which ongoing monitoring and immediate notification by the Investigator to the Sponsor are required. A summary of SAEs and all nonserious AEs ("Other"), regardless of causality, is located in the "Reported Adverse Events" section.

20. Part C: GMT of Serum RSV-A and RSV-B NAbs mRNA-1345 Revaccination Day 29 Compared to Primary Vaccination Day 29

    Time frame: Primary Vaccination Day 29 to Revaccination Day 29

    Antibody values reported as below LLOQ were replaced by 0.5*LLOQ. Values greater than the ULOQ were replaced by the ULOQ. LLOQ was 13 IU/mL and ULOQ was 259061 IU/mL for RSV-A. LLOQ was 10 IU/mL and ULOQ was 112476 IU/mL for RSV-B. mRNA-1345 Revaccination Day 29 and mRNA-1345 primary vaccination Day 29 (received in Part B) are presented.

Results and safety

Loading the posted results from ClinicalTrials.gov…

Research links

• Official record on ClinicalTrials.govLast updated by the sponsor 30 Dec 2025.
• Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
• Derived from this study: PubMed 40988124Goswami J, Cardona JF, Caso J, Hsu DC, Simorellis AK, Wilson L, Dhar R, Wang X, Kapoor A, Collins A, Righi V, Lan L, Du J, Zhou H, Stoszek SK, Shaw CA, Reuter C, Wilson E, Das R. Safety, Tolerability, and Immunogenicity of Revaccination With mRNA-1345, an mRNA Vaccine Against Respiratory Syncytial Virus, Administered 12 Months Following a Primary Dose in Adults Aged >/=50 Years. Clin Infect Dis. 2026 Apr 30;82(4):e855-e862. doi: 10.1093/cid/ciaf515.
• Derived from this study: PubMed 39608389Goswami J, Cardona JF, Hsu DC, Simorellis AK, Wilson L, Dhar R, Tomassini JE, Wang X, Kapoor A, Collins A, Righi V, Lan L, Du J, Zhou H, Stoszek SK, Shaw CA, Reuter C, Wilson E, Miller JM, Das R; study investigators. Safety and immunogenicity of mRNA-1345 RSV vaccine coadministered with an influenza or COVID-19 vaccine in adults aged 50 years or older: an observer-blinded, placebo-controlled, randomised, phase 3 trial. Lancet Infect Dis. 2025 Apr;25(4):411-423. doi: 10.1016/S1473-3099(24)00589-9. Epub 2024 Nov 25.
• Individual participant dataSharing planned: No

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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.

The record lists no contact. Use the official record to reach the sponsor.

62 sites in 1 country: see every site and its status.