A Study to Evaluate the Safety and Efficacy of mRNA-1345 Vaccine Targeting Respiratory Syncytial Virus (RSV) in Adults ≥60 Years of Age
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ClinicalTrials.gov Identifier: NCT05127434 |
Recruitment Status :
Recruiting
First Posted : November 19, 2021
Last Update Posted : January 12, 2022
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Condition or disease | Intervention/treatment | Phase |
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Respiratory Syncytial Virus | Drug: Placebo Drug: mRNA-1345 | Phase 2 Phase 3 |
The study will be conducted in 2 phases: Phase 2 and Phase 3. In the Phase 2 segment, between 400 and 2,000 participants will be randomly assigned to receive a single injection of either mRNA-1345 vaccine at the selected dose or placebo in a 1:1 randomization ratio.
In the Phase 3 segment, between 32,000 and 33,600 participants will be randomly assigned to receive a single injection of either mRNA-1345 vaccine at the selected dose or placebo in a 1:1 randomization ratio.
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 34000 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Primary Purpose: | Prevention |
Official Title: | A Phase 2/3, Randomized, Observer-Blind, Placebo-Controlled Study to Evaluate the Safety and Efficacy of mRNA-1345, an mRNA Vaccine Targeting Respiratory Syncytial Virus (RSV), in Adults ≥60 Years of Age |
Actual Study Start Date : | November 17, 2021 |
Estimated Primary Completion Date : | December 31, 2023 |
Estimated Study Completion Date : | November 30, 2024 |

Arm | Intervention/treatment |
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Experimental: mRNA-1345
Single injection of mRNA-1345 on Day 1.
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Drug: mRNA-1345
Sterile liquid for injection |
Experimental: Placebo
Single injection of mRNA-1345 matching-placebo on Day 1.
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Drug: Placebo
0.9% sodium chloride (normal saline) injection |
- Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs) up to 7 Days Postinjection [ Time Frame: Up to 7 days postinjection ]
- Number of Participants with Unsolicited Adverse Events (AEs) up to 28 Days Postinjection [ Time Frame: Up to 28 days postinjection ]
- Number of Participants With Medically Attended AEs (MAAEs), Adverse Events of Special Interests (AESIs), Serious Adverse Events (SAEs), and AEs Leading to Withdrawal up to 24 Months Postinjection [ Time Frame: Up to 24 months postinjection ]
- Vaccine Efficacy (VE) of mRNA-1345 to Prevent a First Episode of RSV-LRTD within the Period of 14 Days Postinjection up to 12 Months Postinjection [ Time Frame: 14 days postinjection up to 12 months postinjection ]VE of mRNA-1345 to prevent reverse transcription polymerase chain reaction (RT-PCR) confirmed protocol-defined RSV-LRTD, defined as 100*(1-RR), where RR is the ratio of attack rates in the mRNA-1345 group and the placebo group.
- VE of mRNA-1345 to Prevent a First Episode of RSV-Associated Acute Respiratory Disease (RSV-ARD) within the Period of 14 Days Postinjection up to 12 Months Postinjection [ Time Frame: 14 days postinjection up to 12 months postinjection ]VE of mRNA-1345 to prevent RT-PCR confirmed protocol-defined RSV-ARD, defined as 100*(1-RR), where RR is the ratio of attack rates in the mRNA-1345 group and the placebo group.
- VE of mRNA-1345 to Prevent Hospitalizations Associated with RSV-ARD or RSV-LRTD within the Period of 14 Days Postinjection up to 12 Months Postinjection [ Time Frame: 14 days postinjection up to 12 months postinjection ]VE of mRNA-1345 to prevent RT-PCR confirmed protocol-defined RSV-ARD or RSV-LRTD, defined as 100*(1-RR), where RR is the ratio of attack rates in the mRNA-1345 group and the placebo group.
- Geometric Mean Titer (GMT) of Serum RSV Neutralizing and Binding Antibodies (Abs) [ Time Frame: Baseline and 1, 6, 12, 18, and 24 months postinjection ]
- Geometric Mean Fold-Rise of Postbaseline/Baseline Ab Titers [ Time Frame: Baseline and 1, 6, 12, 18, and 24 months postinjection ]
- Proportion of Participants with ≥4-fold Increases in Ab Titers from Baseline [ Time Frame: Baseline and 1, 6, 12, 18, and 24 months postinjection ]

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Ages Eligible for Study: | 60 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Key Inclusion Criteria:
- Adults ≥ 60 years of age who are primarily responsible for self-care and activities of daily living. Participants may have one or more chronic medical diagnoses (specifically chronic heart failure [CHF] and chronic obstructive pulmonary disease [COPD]), but should be medically stable as assessed by the following criteria: absence of changes in medical therapy within 1 month due to treatment failure or toxicity; absence of medical events qualifying as SAEs within 1 month of the planned study injection on Day 1; and absence of known, current, and life-limiting diagnoses, which could continue for the duration of the primary efficacy period (12 months from study injection on Day 1) and which, in the opinion of the investigator, would make completion of the protocol unlikely.
- Body mass index from ≥18 kilograms (kg)/square meter (m^2) to ≤35 kg/m^2.
Key Exclusion Criteria:
- Participation in another clinical research study where participant has received an investigational product (drug/biologic/device) within 45 days before the planned date of the Day 1 vaccination.
- Prior participation in research involving receipt of any investigational RSV product (drug/biologic/device).
- History of a serious reaction to any prior vaccination or Guillain-Barré syndrome within 6 weeks of any prior influenza immunization.
- Received or plans to receive any non-study vaccine within 28 days before or after the Day 1 study injection. The exceptions are seasonal influenza vaccines, pneumococcal vaccines, or authorized or approved vaccines for the prevention of COVID-19 (regardless of type of vaccine), which are not permitted within 14 days before or after the Day 1 study injection. Efforts should be made to space study injection and COVID-19 vaccination by at least 7 and preferably 14 days, but COVID-19 vaccination should not be delayed.
Other inclusion and/or exclusion criteria may apply.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05127434
Contact: Moderna Clinical Trials Support Center | 1-877-777-7187 | clinicaltrials@modernatx.com |

Responsible Party: | ModernaTX, Inc. |
ClinicalTrials.gov Identifier: | NCT05127434 |
Other Study ID Numbers: |
mRNA-1345-P301 |
First Posted: | November 19, 2021 Key Record Dates |
Last Update Posted: | January 12, 2022 |
Last Verified: | December 2021 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Viral Diseases Messenger RNA Moderna mRNA-1345 |
Respiratory syncytial virus Safety Vaccines |
Virus Diseases Infections |