A Study to Evaluate the Efficacy and Safety of mRNA-1283 and mRNA-1273 in Participants 50 to 64 Years of Age Without High-Risk Conditions for Severe Coronavirus Disease 2019 (COVID-19)

April 24, 2026 updated by: ModernaTX, Inc.

A Phase 4, Randomized, Observer-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of mRNA-1283 And mRNA-1273 Variant-Containing Formulation in Adults 50 to 64 Years of Age Without Underlying Conditions That Put Them at High Risk for Severe Outcomes From COVID-19

The purpose of this study is to evaluate the efficacy and safety of mRNA-1283 and mRNA-1273 (variant formulations) in adults 50 to 64 years of age without high risk factors for severe COVID-19.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

30000

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Alabama
      • Birmingham, Alabama, United States, 35216
        • Accel Clinical Research
      • Cullman, Alabama, United States, 35055
        • Cullman Clinical Trials
      • Mobile, Alabama, United States, 36608
        • Velocity Clinical Research, Mobile
      • Mobile, Alabama, United States, 36608
        • AMR Clinical Mobile
    • Arizona
      • Glendale, Arizona, United States, 85308
        • Lenzmeier Family Medicine - Avacare
      • Mesa, Arizona, United States, 85213
        • Desert Clinical Research
      • Phoenix, Arizona, United States, 85006
        • Velocity Clinical Research - Phoenix
      • Phoenix, Arizona, United States, 85044
        • Foothills Research Center/Avacare
      • Scottsdale, Arizona, United States, 85260
        • Headlands Research Scottsdale
      • Tempe, Arizona, United States, 85283
        • Fiel Family and Sports Medicine / Avacare
    • California
      • Colton, California, United States, 92324
        • Avacare
      • Garden Grove, California, United States, 92845
        • CenExel CNR
      • Huntington Park, California, United States, 90255
        • Velocity Clinical Research, Huntington Park
      • La Mesa, California, United States, 91942
        • Velocity Clinical Research - San Diego - ERN - PPDS-Site Number:8400010
      • Los Angeles, California, United States, 90017
        • Velocity Clinical Research - Los Angeles
      • Riverside, California, United States, 92503
        • Artemis Institute for Clinical Research
      • Rolling Hills Estates, California, United States, 90274
        • Peninsula Research Associates
      • San Bernardino, California, United States, 92408
        • Velocity Clinical Research -- Banning
      • San Diego, California, United States, 92103
        • Artemis Institute for Clinical Research
    • Colorado
      • Denver, Colorado, United States, 80238
        • Tekton Research, LLC
      • Fort Collins, Colorado, United States, 80525
        • Tekton Research, LLC
      • Lakewood, Colorado, United States, 80228
        • Critical Care, Pulmonary and Sleep Associates, P.LLP/Avacare
      • Longmont, Colorado, United States, 80501
        • Tekton Research, LLC
    • Connecticut
      • Bridgeport, Connecticut, United States, 06606
        • New England Research Associates
      • Stamford, Connecticut, United States, 06905
        • Stamford Therapeutics Consortium
    • District of Columbia
      • Washington D.C., District of Columbia, United States, 20016
        • Velocity Clinical Research-Washington, DC
    • Florida
      • DeLand, Florida, United States, 32720
        • Hillcrest Medical Research, LLC
      • DeLand, Florida, United States, 32720
        • University Clinical Research-Deland, LLC d/b/a Accel Research Sites - Deland Clinical Research Unit
      • Doral, Florida, United States, 33172
        • Suncoast Research Associates, LLC
      • Hallandale, Florida, United States, 33009
        • Velocity Clinical Research, Hallandale Beach
      • Hialeah, Florida, United States, 33012
        • Indago Research & Health Center, Inc
      • Hollywood, Florida, United States, 33024
        • CenExel Research Centers of America
      • Hollywood, Florida, United States, 33024
        • NextPhase Research Florida
      • Jupiter, Florida, United States, 33458
        • Health Awareness Inc.
      • Lakeland, Florida, United States, 33803
        • Sandhill Research, LLC d/b/a Accel Research Sites - Lakeland Clinical Research Unit
      • Largo, Florida, United States, 33777
        • Sandhill Research, LLC d/b/a Accel Research Sites- St. Pete-Largo Clinical Research Unit
      • Maitland, Florida, United States, 32751
        • Accel Research Sites
      • Miami Lakes, Florida, United States, 33016
        • Global Health Research Center, Inc.
      • New Port Richey, Florida, United States, 34652
        • Suncoast Clinical Research
      • Orlando, Florida, United States, 32819
        • Headlands Research Orlando
      • Palmetto Bay, Florida, United States, 33157
        • Innovation Medical Research Center
      • Tampa, Florida, United States, 33613
        • ForCare Clinical Research
      • Tampa, Florida, United States, 33615
        • Global Health Research Center, Inc.
    • Georgia
      • Albany, Georgia, United States, 31707
        • Javara Inc. and Privia Medical Group of Georgia, LLC
      • Atlanta, Georgia, United States, 30331
        • Atlanta Center for Medical Research
      • Atlanta, Georgia, United States, 30329
        • DelRicht Research
      • Decatur, Georgia, United States, 30030
        • CenExel iResearch, LLC
      • Decatur, Georgia, United States, 30030
        • Accel Research Sites - Neurostudies
      • Fayetteville, Georgia, United States, 30214
        • Javara Inc. and Privia Medical Group of Georgia, LLC
      • Savannah, Georgia, United States, 31406
        • Velocity Clinical Research Savannah
      • Stockbridge, Georgia, United States, 30281
        • Clinical Research Atlanta
    • Idaho
      • Meridian, Idaho, United States, 83642
        • Velocity Clinical Research - Boise - ERN - PPDS
    • Illinois
      • Melrose Park, Illinois, United States, 60160
        • DM Clinical Research - Melrose Park
    • Indiana
      • Valparaiso, Indiana, United States, 46383
        • Velocity Clinical Research Valparaiso
    • Iowa
      • Sioux City, Iowa, United States, 51106
        • Velocity Clinical Research - Sioux City
    • Kansas
      • Lenexa, Kansas, United States, 66212
        • Johnson County Clin-Trials
      • Wichita, Kansas, United States, 67218
        • Tekton Research, LLC
    • Kentucky
      • Louisville, Kentucky, United States, 40205
        • DelRicht Research
      • Versailles, Kentucky, United States, 40383
        • Versailles Family Medicine - CCT Research
    • Louisiana
      • Baton Rouge, Louisiana, United States, 70809
        • Velocity Clinical Research-Baton Rouge
      • Covington, Louisiana, United States, 70433
        • Velocity Clinical Research - Covington
      • Kenner, Louisiana, United States, 70065
        • Avacare
      • Lafayette, Louisiana, United States, 70508
        • Velocity Clinical Research, Lafayette
      • Mandeville, Louisiana, United States, 70471
        • DelRicht Research
      • New Orleans, Louisiana, United States, 70115
        • DelRicht Research
      • New Orleans, Louisiana, United States, 70119
        • Velocity Clinical Research, New Orleans
      • Prairieville, Louisiana, United States, 70769
        • DelRicht Research
    • Maryland
      • Annapolis, Maryland, United States, 21401
        • Annapolis Internal Medicine
      • Columbia, Maryland, United States, 21045
        • Centennial Medical Group
      • Rockville, Maryland, United States, 20854
        • Velocity Clinical Research, Rockville
    • Massachusetts
      • Boston, Massachusetts, United States, 02115
        • Brigham and Women's Hospital
      • Brookline, Massachusetts, United States, 02446
        • DM Clinical Research - Brookline
      • Methuen, Massachusetts, United States, 01844
        • ActivMed Practices & Research, LLC
    • Michigan
      • Southfield, Michigan, United States, 48076
        • DM Clinical Research - Southfield
      • Southfield, Michigan, United States, 48034
        • Headlands Research Detroit
    • Minnesota
      • Mankato, Minnesota, United States, 56001
        • Javara Inc. and Mankato Clinic, Ltd.
    • Mississippi
      • Gulfport, Mississippi, United States, 39503
        • Velocity Clinical Research Gulfport
    • Missouri
      • Chesterfield, Missouri, United States, 63005
        • Clinical Research Professionals
      • Kansas City, Missouri, United States, 64151
        • Clay-Platte Family Medicine Clinic
      • Kansas City, Missouri, United States, 64116
        • AMR Clinical
      • Springfield, Missouri, United States, 65807
        • DelRicht Research
      • St Louis, Missouri, United States, 63141
        • Sundance Clinical Research, LLC
      • Town and Country, Missouri, United States, 63017
        • DelRicht Research
    • Nebraska
      • Fremont, Nebraska, United States, 68025
        • Avacare Research/Methodist Physicians Clinic
      • Grand Island, Nebraska, United States, 68803
        • Velocity Clinical Research, Grand Island
      • Lincoln, Nebraska, United States, 68510
        • Velocity Clinical Research
      • Norfolk, Nebraska, United States, 68701
        • Velocity Clinical Research Norfolk
      • Omaha, Nebraska, United States, 68134
        • Velocity Clinical Research Omaha
      • Omaha, Nebraska, United States, 68144
        • Avacare/Midwest Regional Health Services
      • Papillion, Nebraska, United States, 68046
        • Papillion Research/Avacare
    • Nevada
      • Las Vegas, Nevada, United States, 89119
        • Santa Rosa Medical Centers of Nevada
    • New Jersey
      • Jersey City, New Jersey, United States, 07306
        • DM Clinical Research - Jersey City
    • New Mexico
      • Albuquerque, New Mexico, United States, 87107
        • Velocity Clinical Research - Albuquerque
      • Albuquerque, New Mexico, United States, 87106
        • DM Clinical Research - Albuquerque
    • New York
      • Rochester, New York, United States, 14609
        • Rochester Clinical Research
    • North Carolina
      • Durham, North Carolina, United States, 27701
        • Velocity Clinical Research, Durham
      • Raleigh, North Carolina, United States, 27607
        • Eximia Research - NC, LLC
      • Wilmington, North Carolina, United States, 28403
        • TMA Headlands LLC d/b/a Trial Management Associates
      • Winston-Salem, North Carolina, United States, 27157
        • Wake Forest University Health Sciences
    • Ohio
      • Beachwood, Ohio, United States, 44122
        • Velocity Clinical Research - Cleveland
      • Cincinnati, Ohio, United States, 45212
        • CTI Clinical Research Center
      • Cincinnati, Ohio, United States, 45246
        • Velocity Clinical Research Springdale
      • Cincinnati, Ohio, United States, 45242
        • Velocity Clinical Research-Mt. Auburn
    • Oklahoma
      • Edmond, Oklahoma, United States, 73013
        • Tekton Research, LLC
      • Moore, Oklahoma, United States, 73160
        • Tekton Research, LLC
      • Tulsa, Oklahoma, United States, 74133
        • DelRicht Research
      • Yukon, Oklahoma, United States, 73099
        • Tekton Research, LLC
    • Oregon
      • Medford, Oregon, United States, 97504
        • Velocity Clinical Research - Medford
      • Portland, Oregon, United States, 97210
        • Summit Headlands LLC
    • Pennsylvania
      • Horsham, Pennsylvania, United States, 19044
        • Hatboro Medical Associates/Avacare
      • Philadelphia, Pennsylvania, United States, 19107
        • DM Clinical Research - Philadelphia
    • Rhode Island
      • East Greenwich, Rhode Island, United States, 02818
        • Velocity Clinical Research - East Greenwich
    • South Carolina
      • Anderson, South Carolina, United States, 29621
        • Velocity Clinical Research, Anderson
      • Charleston, South Carolina, United States, 29407
        • DelRicht Research
      • Columbia, South Carolina, United States, 29204
        • Velocity Clinical Research - Columbia
      • North Charleston, South Carolina, United States, 29405
        • Coastal Carolina Research Center, LLC
      • Spartanburg, South Carolina, United States, 29303
        • Velocity Clinical Research Spartanburg
      • Union, South Carolina, United States, 29379
        • Velocity Clinical Research Union
    • Tennessee
      • Hendersonville, Tennessee, United States, 37075
        • DelRicht Research
    • Texas
      • Abilene, Texas, United States, 79606
        • Velocity Clinical Research, Abilene
      • Austin, Texas, United States, 78745
        • Tekton Research, LLC
      • Austin, Texas, United States, 78759
        • Velocity Clinical Research - Austin
      • Beaumont, Texas, United States, 77706
        • Tekton Research, LLC
      • Conroe, Texas, United States, 77384
        • Javara Inc. and Privia Medical Group Gulf Coast, PLLC
      • Dallas, Texas, United States, 75230
        • Velocity Clinical Research - Dallas
      • Fort Worth, Texas, United States, 76135
        • Avacare
      • Houston, Texas, United States, 77065
        • DM Clinical Research - Houston
      • Houston, Texas, United States, 77081
        • DM Clinical Research - Houston
      • Prosper, Texas, United States, 75078
        • DelRicht Research
      • Round Rock, Texas, United States, 78681
        • Be Well Clinical Studies
      • San Antonio, Texas, United States, 78207
        • DM Clinical Research - San Antonio
      • San Antonio, Texas, United States, 78229
        • Tekton Research, LLC
      • San Marcos, Texas, United States, 78666
        • Javara Inc. and Privia Medical Group Gulf Coast, PLLC
      • Stephenville, Texas, United States, 76401
        • Javara Inc. and Privia Medical Group - North Texas
      • Sugar Land, Texas, United States, 77478
        • DM Clinical Research - Sugar Land
      • Sugar Land, Texas, United States, 77478
        • Javara Inc. and Privia Medical Group Gulf Coast, PLLC
      • Sugar Land, Texas, United States, 77479
        • Olympus Clinical Research
      • Tomball, Texas, United States, 77375
        • DM Clinical Research - Tomball
    • Utah
      • Bountiful, Utah, United States, 84010
        • Cope Family Medicine / Avacare
      • Pleasant View, Utah, United States, 84404
        • Mountain View/Avacare
      • Salt Lake City, Utah, United States, 84107
        • JBR Clinical Research
      • Salt Lake City, Utah, United States, 84117
        • Olympus Family Medicine/Avacare
      • South Jordan, Utah, United States, 84095
        • J. Lewis Research, Inc/Jordan River Family Medicine
      • South Ogden, Utah, United States, 84405
        • South Ogden Family Medicine/ Avacare
      • West Jordan, Utah, United States, 84088
        • Velocity Clinical Research - Salt Lake City (West Jordan)
    • Virginia
      • Charlottesville, Virginia, United States, 22911
        • Charlottesville Medical Research, LLC
      • Hampton, Virginia, United States, 23666
        • Velocity Clinical Research-Hampton
      • Richmond, Virginia, United States, 23226
        • Clinical Research Partners, LLC
      • Suffolk, Virginia, United States, 23435
        • Velocity Clinical Research - Suffolk
    • Washington
      • Spokane, Washington, United States, 99218
        • Velocity Clinical Research, Spokane

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Key Inclusion Criteria:

  • Healthy and without underlying medical conditions that may put them at higher risk of experiencing severe outcomes of COVID-19, as determined by medical evaluation including medical history, physical examination, laboratory tests, and cardiac monitoring.

Key Exclusion Criteria:

  • History of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection within 3 months prior to enrollment.
  • Acutely ill or febrile within 72 hours prior to or at the Screening Visit or Day 1.

  • Receipt of any of the following:

    • COVID-19 vaccine within 3 months prior to enrollment,
    • Any licensed non COVID-19 vaccine within 28 days before or planned receipt within 28 days after the study intervention, except an influenza vaccine, which may be given 14 days before or after receipt of the study intervention,
    • Corticosteroids at ≥10 milligrams (mg)/day of prednisone or equivalent for >14 days in total within 90 days prior to Day 1 or is anticipating the need for corticosteroids at any time during the study or,
    • Systemic immunosuppressive treatment within 180 days prior to the Screening or is anticipating the need for systemic immunosuppressive treatment at any time during participation in the study.
  • Has donated ≥450 mL of blood products within 28 days prior to the Screening Visit or plans to donate blood products within 28 days post study injection.
  • Has participated in an investigational 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.

Note: Additional inclusion/exclusion criteria may apply, per protocol.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: mRNA-1273 (Variant Formulation)
Participants will receive a single intramuscular (IM) injection of mRNA-1273 on Day 1.
Biological: mRNA-1273
Sterile liquid for injection
Experimental: mRNA-1283 (Variant Formulation)
Participants will receive a single IM injection of mRNA-1283 on Day 1.
Biological: mRNA-1283
Sterile liquid for injection
Placebo Comparator: Placebo
Participants will receive a single IM injection of placebo on Day 1.
Biological: Placebo
0.9% sodium chloride (normal saline) injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
VE of mRNA-1273 (Variant Formulation) to Prevent the First Event of Symptomatic COVID-19 after Study Injection
Time Frame: Day 1 through Day 181
The VE is defined as the percent reduction in the hazard of the first event of symptomatic COVID-19 after study injection (each vaccine arm versus placebo) and will be estimated using 1-hazard ratio (HR).
Day 1 through Day 181
Vaccine Efficacy (VE) of mRNA-1283 (Variant Formulation) to Prevent the First Event of Symptomatic COVID-19 after Study Injection
Time Frame: Day 1 through Day 181
The VE is defined as the percent reduction in the hazard of the first event of symptomatic COVID-19 after study injection (each vaccine arm versus placebo) and will be estimated using 1-hazard ratio (HR).
Day 1 through Day 181
Number of Participants with Unsolicited Adverse Events (AEs)
Time Frame: Day 1 through Day 28
Day 1 through Day 28
Number of Participants with Serious AEs (SAEs), Medically Attended AEs (MAAEs), AEs of Special Interest (AESIs), and AEs Leading to Discontinuation
Time Frame: Day 1 through Day 181
Day 1 through Day 181

Secondary Outcome Measures

Outcome Measure
Time Frame
Number of Participants with a First Event of Severe COVID-19 after Study Injection
Time Frame: Day 1 through Day 181
Day 1 through Day 181

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

ModernaTX, Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 26, 2025

Primary Completion (Estimated)

June 16, 2027

Study Completion (Estimated)

June 16, 2027

Study Registration Dates

First Submitted

November 25, 2025

First Submitted That Met QC Criteria

November 25, 2025

First Posted (Actual)

December 5, 2025

Study Record Updates

Last Update Posted (Actual)

April 28, 2026

Last Update Submitted That Met QC Criteria

April 24, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • mRNA-1273_1283-P401

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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