SARS-CoV-2Phase 2NCT07808697
A Study to Evaluate the Safety, Reactogenicity, and Immunogenicity of mRNA-1283 in Participants ≥6 Months to <12 Years of Age
A Phase 2 study testing mRNA-1283 and mRNA-1273 in people with SARS-CoV-2, run by ModernaTX, Inc. at 31 sites in 6 countries.
Trial summary
This study will evaluate 2 dose levels of mRNA-1283 in participants ≥6 months to <12 years to determine the optimal dose level per age group. Read more about this study
- Who is it for?
- Ages 6 months to 11 yearsHealthy volunteers can take part
- Conditions the study is for
- SARS-CoV-2
- What is being tested?
- mRNA-1283 and mRNA-1273
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 300 participants
- Where
- 31 sitesin 6 countries
- Study dates
- 1 Sep 2026to 30 Aug 2029
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 6 months to 11 years
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- Participant is male or female, between ≥2 years to <12 years of age for Cohort 1 or ≥6 months to <2 years of age for Cohort 2 (calculated from date of birth) at the time of signing the informed consent/assent.
- Participant is in good general health as determined by medical evaluation including medical history and physical examination. Participants with chronic but stable conditions (eg, gastroesophageal reflux disease, asthma) may be eligible to enroll, provided the condition is well-controlled and not expected to interfere with study participation or outcomes.
- For participants in Cohort 2: the participant was born at ≥37 weeks, with a minimum birth weight of 2.5 kilograms, without fetal growth restriction.
- Female participants of nonchildbearing potential may be enrolled in the study. Nonchildbearing potential is defined as premenarche. The investigator is responsible for review of medical history, menstrual history, and recent sexual activity to decrease the risk for inclusion of a participant with an early undetected pregnancy. If childbearing potential is unclear (for example, amenorrhea in athletes) and a menstrual cycle cannot be confirmed before first dose of study intervention, additional evaluation should be considered.
- Female participants who have reached menarche may be enrolled in the study if all of the following criteria are fulfilled:
- Has a negative highly sensitive pregnancy test (urine or serum) as required by local regulations within 24 hours before the study intervention.
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- Is not currently chest/breastfeeding.
- Has been using a highly effective contraceptive method or has abstained from all activities that could lead to pregnancy for at least 28 days prior to the study injection (Day 1). The investigator should evaluate the potential for contraceptive method failure (for example, noncompliance, recently initiated) in relationship to the study injection.
- Has agreed to continue adequate contraception through the end of study. Contraceptive use by participants should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.
Who cannot join
- History of SARS-CoV-2 infection within 3 months prior to enrollment.
- Acutely ill or febrile (temperature ≥38.0℃elsius [100.4°Fahrenheit]) within 72 hours prior to or at the screening visit or Day 1. Participants who are acutely ill or febrile may be scheduled for a separate dosing visit within the protocol-specified window for screening and will retain their initially assigned participant number. Afebrile participants with minor illnesses can be enrolled at the discretion of the Investigator.
- Any medical, psychiatric, or occupational condition, including reported history of drug, or alcohol abuse in the parent(s)/ legally authorized representative(s), that, in the opinion of the investigator, might pose additional risk due to child's participation in the study, could interfere with safety assessments, or could interfere with the interpretation of study results.
- Receipt of the 2026-2027 formulation of a COVID-19 vaccine at any time prior to enrollment.
- Receipt of any COVID-19 vaccine within 6 months prior to enrollment.
- Receipt of any nonstudy vaccination within 14 days (28 days for live vaccines) prior to study intervention or plans to receive a nonstudy vaccine through 14 days after administration of study intervention.
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- Received systemic immunosuppressive treatment, including long-acting biological therapies that affect immune responses (for example, infliximab), within 180 days prior to Day 1 (baseline) or plans to do so during the study.
- Received systemic immunoglobulins or blood products within 90 days prior to the screening visit or plans to receive them during the study. Exception: Nirsevimab and clesrovimab are allowed.
- For infants who receive breast milk, maternal receipt of systemic immunosuppressive therapy during lactation. This includes ≥10 milligrams/day of prednisone or equivalent for 14 days or more, or other immunomodulating agents (for example, biologics, calcineurin inhibitors, disease-modifying agents) that may be transferred via breastmilk and impact infant immune development or vaccine response.
- Has 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.
- Has been placed under the control or protection of an agency, organization, institution, or entity by the courts, the government, or a government body, acting in accordance with powers conferred on them by laws, and regulation. Does not include a child who is adopted or has an appointed legal guardian.
- Receipt of any nonstudy vaccination within 14 days (28 days for live vaccines) prior to study intervention or plans to receive a nonstudy vaccine through 14 days after administration of study intervention.
- History of any myocarditis, pericarditis, or myopericarditis
- Note: Other inclusion and exclusion criteria may apply.
Trial locations and contacts
31 sites in 6 countries. Contact the study team or a site near you to ask about taking part.
31 sites in 6 countries
United States13 sites
REX Clinical Trials
Beaumont, Texas, 77701
PanAmerican Clinical Research, LLC.
Brownsville, Texas, 78520
Eagle Clinical Research, LLC
Chicago, Illinois, 60621
Hope Research Network
Miami, Florida, 33166
Spotlight Research Center - Internal Medicine
Miami, Florida, 33167
Indago Research and Health Cen
Miami Lakes, Florida, 33016
Orange County Research Center
Ontario, California, 91762
Clinical Research Partners
Richmond, Virginia, 23226
Childrens Hospital Regional Medical Center
Seattle, Washington, 98105
Senders Pediatrics
South Euclid, Ohio, 44121
South Ogden Family Medicine
South Ogden, Utah, 84403
Great Lakes Research Institute -Southfield
Southfield, Michigan, 48075
MplusM - D&H Tamarac Research Center
Tamarac, Florida, 33321
Mexico5 sites
Centro de Investigacion Clínica y Medicina Traslacional (CIMeT)
Guadalajara, Jalisco
Hospital Infantil de México Federico Gómez - Pediatric Gastroenterology
Mexico City, Mexico City
Instituto Nacional de Pediatria
Mexico City, Mexico City
PanAmerican Clinical Research - Queretaro
Querétaro City, Querétaro
Centro de Salud Tizimin
Tizimín, Yucatán
Dominican Republic4 sites
Medvacplus Srl Fundacion Clinica Cruz Jiminian
Cristo Rey, Distrito Nacional (Santo Domingo), 10501
Hospital General y de Especialidades Nuestra Señora de la Altagracia
Salvaleón de Higüey, La Altagracia Province
Instituto Dermatologico y Cirugia de Piel ''Dr. Huberto Bogaert Diaz'' (IDCP-DHBD)
Santo Domingo, Distrito Nacional (Santo Domingo), 10306
Hospital Materno Infantil San Lorenzo De Los Mina
Santo Domingo, Nacional, 11901
Panama4 sites
CEVAXIN Avenida Mexico
Calidonia, Provincia de Panamá, 7094
CEVAXIN Chorrera
La Chorrera, Provincia de Panamá
CEVAXIN 24 de Diciembre
Panama City, Provincia de Panamá
Instituto de Investigaciones Cienti-ficas Y Servicios de Alta Tecnologia Asociacion de Interes Panama; . Centro de Investigación, Innovación y Gestión del Conocimiento de Ciudad de la Salud, Caja de Seguro social
Panama City, Provincia de Panamá
Argentina3 sites
Instituto Medico de la Fundacion Estudios Clinicos
Casilda, Santa Fe Province
Fundacion Respirar - Consultorios Medicos Dra De Salvo
Ciudad Autonoma, Buenos Aires
Hospital del Nino Jesus
San Miguel de Tucumán, Tucumán Province
Puerto Rico2 sites
Ponce Health Sciences University
Ponce, Puerto Rico
BRCR Global
San Juan, Puerto Rico, 00907
About this study
Official title: A Phase 2, Randomized, Observer-Blind, Dose Ranging Study to Evaluate the Safety, Reactogenicity, and Immunogenicity of mRNA-1283 in Participants ≥6 Months to <12 Years of Age
This study will evaluate 2 dose levels of mRNA-1283 in participants ≥6 months to <12 years to determine the optimal dose level per age group.
Read the detailed description
mRNA-1283 will be administered at 2 different dose levels (Dose Level 1 and Dose Level 2), with mRNA-1273 serving as the active comparator. Dose Level 1 will be the lower dose, and Dose Level 2 will be the higher dose.
The study will consist of 2 cohorts. In Cohort 1, mRNA-1283 will be administered as a single dose to participants aged ≥2 to <12 years, regardless of prior coronavirus disease 2019 (COVID-19) vaccination status, with mRNA-1273 included as a comparator. In Cohort 2, mRNA-1283 will be administered as a 2-dose series to participants aged ≥6 months to <2 years who are previously unvaccinated for COVID-19, with mRNA-1273 included as a comparator.
- Conditions
- SARS-CoV-2
- Being tested
- mRNA-1283, mRNA-1273
- Keywords
- mRNA-1283, mRNA-1283 vaccine, mRNA-1273, mRNA-1273 vaccine, SARS-CoV-2, SARS-CoV-2 Vaccine, Coronavirus, Virus Diseases, Messenger RNA, COVID-19, COVID-19 Vaccine, Moderna
- Medical subject headings
- Coronavirus Infections, Virus Diseases, COVID-19
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
mRNA-1283Biological
Sterile liquid for injection
mRNA-1273Biological
Sterile liquid for injection
| Study group | Role | What they receive |
|---|---|---|
| Cohort 1: mRNA-1283 Dose Level 1 | Experimental | Participants aged 2 to <12 years receive one IM dose of on Day 1. Receives: Biological: mRNA-1283 |
| Cohort 1: mRNA-1283 Dose Level 2 | Experimental | Participants aged 2 to <12 years receive one IM dose of on Day 1. Receives: Biological: mRNA-1283 |
| Cohort 1: mRNA-1273 | Active comparator | Participants aged 2 to <12 years receive one IM dose of on Day 1. Receives: Biological: mRNA-1273 |
| Cohort 2: mRNA-1283 Dose Level 1 | Experimental | Participants aged 6 months to <2 years receive two IM doses 28 days apart (Days 1 and 29). Receives: Biological: mRNA-1283 |
| Cohort 2: mRNA-1283 Dose Level 2 | Experimental | Participants aged 6 months to <2 years receive two IM doses of 28 days apart (Days 1 and 29). Receives: Biological: mRNA-1283 |
| Cohort 2: mRNA-1273 | Active comparator | Participants aged 6 months to <2 years receive two IM doses 28 days apart (Day 1 and 29). Receives: Biological: mRNA-1273 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Cohort 1 and Cohort 2: Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs)
Measured: Day 1 through Day 7; 7 Days following injection
Cohort 1 and Cohort 2: Number of Participants with Unsolicited Adverse Events (AEs)
Measured: Day 1 through Day 28 (Cohort 1); 28 Days following injection (Cohort 2)
Cohort 1 and Cohort 2: Number of Participants with Any Medically Attended AEs (MAAEs), Serious AEs (SAEs), AEs of Special Interest (AESIs), and AEs Leading to Discontinuation from the Study
Measured: Day 1 through End of Study (Month 13)
Cohort 1 and Cohort 2: Geometric Mean Value of Antibody Level Against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Target Variant
Measured: Day 29 VISIT (Cohort 1), Day 57 VISIT (Cohort 2)
Cohort 1 and Cohort 2: Geometric Mean Fold Rise of Antibody Level Against SARS-CoV-2
Measured: Day 29 (Cohort 1), Day 57 (Cohort 2)
Cohort 1 and Cohort 2: Number of Participants with Seroresponse Rate
Measured: Day 29 (Cohort 1), Day 57 (Cohort 2)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Sep 2026
- Study start1 Sep 2026 (estimated)
- Primary completion30 Aug 2029 (estimated)
- Study completion30 Aug 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for SARS-CoV-2Studies of the same condition, open and under way.
- More trials run by ModernaTX, Inc.The sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 300 participants (estimated)
Sponsor and investigators
- Lead sponsor
- ModernaTX, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07808697
- Sponsor's protocol ID
- mRNA-1283-P202
- Status last verified
- Sep 2026
- First submitted
- 2 Sep 2026
- Last updated
- 9 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 9 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 2, Randomized, Observer-Blind, Dose Ranging Study to Evaluate the Safety, Reactogenicity, and Immunogenicity of mRNA-1283 in Participants ≥6 Months to <12 Years of Age
- ClinicalTrials.gov ID
- NCT07808697
- Acronym / sponsor ID
- mRNA-1283-P202
- Conditions
- SARS-CoV-2
- Keywords
- mRNA-1283, mRNA-1283 vaccine, mRNA-1273, mRNA-1273 vaccine, SARS-CoV-2, SARS-CoV-2 Vaccine, Coronavirus, Virus Diseases
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 300 participants (estimated)
- Lead sponsor
- ModernaTX, Inc.Industry (pharma, biotech, devices)
- Study start
- 1 Sep 2026 (estimated)
- Primary completion
- 30 Aug 2029 (estimated)
- Study completion
- 30 Aug 2029 (estimated)
- First posted
- 9 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study will evaluate 2 dose levels of mRNA-1283 in participants ≥6 months to <12 years to determine the optimal dose level per age group.
Detailed description
mRNA-1283 will be administered at 2 different dose levels (Dose Level 1 and Dose Level 2), with mRNA-1273 serving as the active comparator. Dose Level 1 will be the lower dose, and Dose Level 2 will be the higher dose.
The study will consist of 2 cohorts. In Cohort 1, mRNA-1283 will be administered as a single dose to participants aged ≥2 to <12 years, regardless of prior coronavirus disease 2019 (COVID-19) vaccination status, with mRNA-1273 included as a comparator. In Cohort 2, mRNA-1283 will be administered as a 2-dose series to participants aged ≥6 months to <2 years who are previously unvaccinated for COVID-19, with mRNA-1273 included as a comparator.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 6
| Arm | Type | Receives |
|---|---|---|
| Cohort 1: mRNA-1283 Dose Level 1 | Experimental | Biological: mRNA-1283Participants aged 2 to <12 years receive one IM dose of on Day 1. |
| Cohort 1: mRNA-1283 Dose Level 2 | Experimental | Biological: mRNA-1283Participants aged 2 to <12 years receive one IM dose of on Day 1. |
| Cohort 1: mRNA-1273 | Active comparator | Biological: mRNA-1273Participants aged 2 to <12 years receive one IM dose of on Day 1. |
| Cohort 2: mRNA-1283 Dose Level 1 | Experimental | Biological: mRNA-1283Participants aged 6 months to <2 years receive two IM doses 28 days apart (Days 1 and 29). |
| Cohort 2: mRNA-1283 Dose Level 2 | Experimental | Biological: mRNA-1283Participants aged 6 months to <2 years receive two IM doses of 28 days apart (Days 1 and 29). |
| Cohort 2: mRNA-1273 | Active comparator | Biological: mRNA-1273Participants aged 6 months to <2 years receive two IM doses 28 days apart (Day 1 and 29). |
Who may qualify
- Ages
- 6 months to 11 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
Key inclusion criteria (9 listed)
- Participant is male or female, between ≥2 years to <12 years of age for Cohort 1 or ≥6 months to <2 years of age for Cohort 2 (calculated from date of birth) at the time of signing the informed consent/assent.
- Participant is in good general health as determined by medical evaluation including medical history and physical examination. Participants with chronic but stable conditions (eg, gastroesophageal reflux disease, asthma) may be eligible to enroll, provided the condition is well-controlled and not expected to interfere with study participation or outcomes.
- For participants in Cohort 2: the participant was born at ≥37 weeks, with a minimum birth weight of 2.5 kilograms, without fetal growth restriction.
- Female participants of nonchildbearing potential may be enrolled in the study. Nonchildbearing potential is defined as premenarche. The investigator is responsible for review of medical history, menstrual history, and recent sexual activity to decrease the risk for inclusion of a participant with an early undetected pregnancy. If childbearing potential is unclear (for example, amenorrhea in athletes) and a menstrual cycle cannot be confirmed before first dose of study intervention, additional evaluation should be considered.
- Female participants who have reached menarche may be enrolled in the study if all of the following criteria are fulfilled:
Key exclusion criteria (14 listed)
- History of SARS-CoV-2 infection within 3 months prior to enrollment.
- Acutely ill or febrile (temperature ≥38.0℃elsius [100.4°Fahrenheit]) within 72 hours prior to or at the screening visit or Day 1. Participants who are acutely ill or febrile may be scheduled for a separate dosing visit within the protocol-specified window for screening and will retain their initially assigned participant number. Afebrile participants with minor illnesses can be enrolled at the discretion of the Investigator.
- Any medical, psychiatric, or occupational condition, including reported history of drug, or alcohol abuse in the parent(s)/ legally authorized representative(s), that, in the opinion of the investigator, might pose additional risk due to child's participation in the study, could interfere with safety assessments, or could interfere with the interpretation of study results.
- Receipt of the 2026-2027 formulation of a COVID-19 vaccine at any time prior to enrollment.
- Receipt of any COVID-19 vaccine within 6 months prior to enrollment.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| mRNA-1283Sterile liquid for injection | Biological | Cohort 1: mRNA-1283 Dose Level 1, Cohort 1: mRNA-1283 Dose Level 2, Cohort 2: mRNA-1283 Dose Level 1, Cohort 2: mRNA-1283 Dose Level 2 |
| mRNA-1273Sterile liquid for injection | Biological | Cohort 1: mRNA-1273, Cohort 2: mRNA-1273 |
Primary outcome
Cohort 1 and Cohort 2: Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs)
Time frame: Day 1 through Day 7; 7 Days following injection
Cohort 1 and Cohort 2: Number of Participants with Unsolicited Adverse Events (AEs)
Time frame: Day 1 through Day 28 (Cohort 1); 28 Days following injection (Cohort 2)
Cohort 1 and Cohort 2: Number of Participants with Any Medically Attended AEs (MAAEs), Serious AEs (SAEs), AEs of Special Interest (AESIs), and AEs Leading to Discontinuation from the Study
Time frame: Day 1 through End of Study (Month 13)
Cohort 1 and Cohort 2: Geometric Mean Value of Antibody Level Against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Target Variant
Time frame: Day 29 VISIT (Cohort 1), Day 57 VISIT (Cohort 2)
Cohort 1 and Cohort 2: Geometric Mean Fold Rise of Antibody Level Against SARS-CoV-2
Time frame: Day 29 (Cohort 1), Day 57 (Cohort 2)
Cohort 1 and Cohort 2: Number of Participants with Seroresponse Rate
Time frame: Day 29 (Cohort 1), Day 57 (Cohort 2)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Sep 2026.
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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.
31 sites in 6 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing mRNA-1283 and mRNA-1273 in people with SARS-CoV-2, run by ModernaTX, Inc. at 31 sites in 6 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 9 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 9 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 31 sites in United States, Mexico, Dominican Republic, Panama, Argentina and 1 more country. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Moderna WeCare Team (1-866-663-3762, WeCareClinicalTrials@modernatx.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Cohort 1 and Cohort 2: Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs) (time frame: Day 1 through Day 7; 7 Days following injection). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Sep 2026.