A Study to Evaluate Safety, Reactogenicity, and Immunogenicity of mRNA-1283 and mRNA-1273 Vaccines in Healthy Adults Between 18 Years and 55 Years of Age to Prevent COVID-19

Study Overview
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Brief Summary
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The primary goal for this study is to evaluate the safety and reactogenicity of 3 dose levels of mRNA-1283 and 1 dose level of mRNA-1273 vaccine given to healthy adults in 2 doses, 28 days apart, and 1 dose level of mRNA-1283 administered as a single dose to healthy adults.

Official Title
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A Phase 1, Randomized, Observer-Blind, Dose-Ranging Study to Evaluate the Safety, Reactogenicity, and Immunogenicity of mRNA-1283 and mRNA-1273 SARS-CoV-2 Vaccine in Adults Aged 18-55 Years

Conditions
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SARS-CoV-2

Intervention / Treatment
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* Biological: mRNA-1283
* Biological: mRNA-1273
* Biological: Placebo


Participation Criteria
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Eligibility Criteria
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Key Inclusion Criteria: Understands and agrees to comply with the study procedures and provides written informed consent. According to the assessment of the investigator, is in good general health and can comply with study procedures. Body mass index (BMI) of 18 kilograms/square meter (kg/m^2) to 35 kg/m^2 (inclusive) at the Screening Visit (Day 0). For female participants of childbearing potential: negative pregnancy test, adequate contraception or has abstained from all activities that could result in pregnancy for at least 28 days prior to the first injection, agreement to continue adequate contraception or abstinence through 3 months following the second injection, and not currently breastfeeding. Key Exclusion Criteria: Known history of SARS-CoV-2 infection or known exposure to someone with SARS-CoV-2 infection or COVID-19 in the past 30 days. Positive serology results for SARS-CoV-2 at the Screening Visit. A negative serological test for SARS-CoV-2, performed on a blood sample obtained at the Screening Visit, is required before a participant can be dosed. Travel outside of the United States in the 28 days prior to the Screening Visit (Day 0). Prior administration of an investigational, authorized, or licensed CoV (for example, SARS-CoV-2, SARS-CoV, or Middle East Respiratory Syndrome [MERS]-CoV) vaccine, based on medical history interview. Current treatment with investigational agents for prophylaxis against COVID-19. Recent (within the last 12 months) use of a dermal filler. Has a medical, psychiatric, or occupational condition that may pose additional risk as a result of participation or that could interfere with safety assessments or interpretation of results according to the investigator's judgment. Has received systemic immunosuppressants or immune-modifying drugs for >14 days in total within 6 months prior to Screening (for corticosteroids, 10 milligrams (mg)/day of prednisone equivalent) or is anticipating the need for immunosuppressive treatment at any time during participation in the study. Has received or plans to receive any licensed vaccine 28 days prior to the first injection (Day 1) or plans to receive a licensed vaccine within 28 days before or after any study injection, with the exception of licensed influenza vaccines, which may be received more than 14 days before the first study injection or more than 14 days after the second study injection. Receipt of systemic immunoglobulins or blood products within 3 months prior to the Screening Visit (Day 0) or plans for receipt during the study. Current use of any inhaled substance (for example, tobacco or cannabis smoke, nicotine vapors). History of chronic smoking (1 cigarette a day) within 1 year of the Screening Visit. Resides in a nursing home. Has donated 450 milliliters (mL) of blood products within 28 days prior to the Screening Visit or plans to donate blood products during the study. Participated in an interventional clinical study within 28 days prior to the Screening Visit based on the medical history interview or plans to do so while participating in this study.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: mRNA-1283 Dose Level 1<br>Participants will receive 2 intramuscular (IM) injections of mRNA-1283 at Dose Level 1 on Day 1 and Day 29. | Biological: mRNA-1283<br>* Sterile liquid for injection<br>|
| Experimental: mRNA-1283 Dose Level 2<br>Participants will receive 2 IM injections of mRNA-1283 at Dose Level 2 on Day 1 and Day 29. | Biological: mRNA-1283<br>* Sterile liquid for injection<br>|
| Experimental: mRNA-1283 Dose Level 3<br>Participants will receive 2 IM injections of mRNA-1283 at Dose Level 3 on Day 1 and Day 29. | Biological: mRNA-1283<br>* Sterile liquid for injection<br>|
| Experimental: mRNA-1273<br>Participants will receive 2 IM injections of mRNA-1273 at a pre-specified dose for this study on Day 1 and Day 29. | Biological: mRNA-1273<br>* Sterile liquid for injection<br>|
| Experimental: Placebo / mRNA-1283<br>Participants will receive 1 IM injection of study drug-matching placebo on Day 1 and 1 IM injection of mRNA-1283 at a pre-specified dose on Day 29. Participants may be offered an opportunity to receive an additional injection of mRNA-1273 at the pre-specified dose on Open-Label Day 1. | Biological: mRNA-1283<br>* Sterile liquid for injection<br>Biological: Placebo<br>* 0.9% sodium chloride (normal saline) injection<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants with Solicited Local and Systemic Reactogenicity Adverse Reactions (ARs) |  | Up to Day 36 (7 days after second dose) | 
| Number of Participants with Unsolicited Adverse Events (AEs) |  | Up to Day 57 (28 days after second dose) | 
| Number of Participants with Medically-Attended AEs (MAAEs), AE of Special Interest (AESIs), and Serious Adverse Events (SAEs) |  | Up to Day 394 (1 year after second dose) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Geometric Mean (GM) of SARS-CoV-2 Specific Neutralizing Antibody (nAb) |  | Day 1, Day 29, Day 36, Day 57, Day 209, and Day 394 | 
| GM of SARS-CoV-2-Specific Binding Antibody (bAb) |  | Day 1, Day 29, Day 36, Day 57, Day 209, and Day 394 | 
| Seroconversion as Measured by an Increase of SARS-CoV-2-Specific nAb Titer or bAb Titer | Seroconversion measured as defined for the study. | Day 1, Day 29, Day 36, Day 57, Day 209, and Day 394 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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COVID-19, COVID-19 Vaccine, Moderna, mRNA-1283 vaccine, mRNA-1273, mRNA-1273 vaccine, SARS-CoV-2, SARS-CoV-2 Vaccine, Coronavirus, Virus Diseases, Messenger RNA