A Study to Evaluate Safety, Reactogenicity, and Immunogenicity of mRNA-1283 and mRNA-1273 Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Vaccines in Healthy Adults Between 18 Years and 55 Years of Age

Study Purpose

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.

Recruitment Criteria

Accepts Healthy Volunteers

Healthy volunteers are participants who do not have a disease or condition, or related conditions or symptoms

Study Type

An interventional clinical study is where participants are assigned to receive one or more interventions (or no intervention) so that researchers can evaluate the effects of the interventions on biomedical or health-related outcomes.

An observational clinical study is where participants identified as belonging to study groups are assessed for biomedical or health outcomes.

Searching Both is inclusive of interventional and observational studies.

Eligible Ages 18 Years - 55 Years
Gender All
More Inclusion & Exclusion Criteria


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.

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.

Trial Details

Trial ID:

This trial id was obtained from ClinicalTrials.gov, a service of the U.S. National Institutes of Health, providing information on publicly and privately supported clinical studies of human participants with locations in all 50 States and in 196 countries.


Phase 1: Studies that emphasize safety and how the drug is metabolized and excreted in humans.

Phase 2: Studies that gather preliminary data on effectiveness (whether the drug works in people who have a certain disease or condition) and additional safety data.

Phase 3: Studies that gather more information about safety and effectiveness by studying different populations and different dosages and by using the drug in combination with other drugs.

Phase 4: Studies occurring after FDA has approved a drug for marketing, efficacy, or optimal use.

Phase 1
Lead Sponsor

The sponsor is the organization or person who oversees the clinical study and is responsible for analyzing the study data.

ModernaTX, Inc.
Principal Investigator

The person who is responsible for the scientific and technical direction of the entire clinical study.

Principal Investigator Affiliation N/A
Agency Class

Category of organization(s) involved as sponsor (and collaborator) supporting the trial.

Overall Status Recruiting
Countries United States

The disease, disorder, syndrome, illness, or injury that is being studied.

Arms & Interventions


Experimental: mRNA-1283 Dose Level 1

Participants will receive 2 intramuscular (IM) injections of mRNA-1283 at Dose Level 1 on Day 1 and Day 29.

Experimental: mRNA-1283 Dose Level 2

Participants will receive 2 IM injections of mRNA-1283 at Dose Level 2 on Day 1 and Day 29.

Experimental: mRNA-1283 Dose Level 3

Participants will receive 2 IM injections of mRNA-1283 at Dose Level 3 on Day 1 and Day 29.

Experimental: mRNA-1273

Participants will receive 2 IM injections of mRNA-1273 at a pre-specified dose for this study on Day 1 and Day 29.

Experimental: Placebo / mRNA-1283

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.


Biological: - mRNA-1283

Sterile liquid for injection

Biological: - mRNA-1273

Sterile liquid for injection

Biological: - Placebo

0.9% sodium chloride (normal saline) injection

Contact a Trial Team

If you are interested in learning more about this trial, find the trial site nearest to your location. We also strongly recommend that you consult with your healthcare provider about the trials that may interest you. Please note all sites listed may not currently be active in the trial. Please continue to check back for additional site locations.

Optimal Research San Diego, LLC, San Diego, California




Optimal Research San Diego, LLC

San Diego, California, 92108

Optimal Research Melbourne, LLC, Melbourne, Florida




Optimal Research Melbourne, LLC

Melbourne, Florida, 32934

Optimal Research Illinois, LLC, Peoria, Illinois




Optimal Research Illinois, LLC

Peoria, Illinois, 61614

Optimal Research Texas, LLC, Austin, Texas




Optimal Research Texas, LLC

Austin, Texas, 78705