COVID-19Phase 4NCT07089706
A Study to Evaluate the Immunogenicity and Safety of mRNA-1283 COVID-19 Variant-containing Formulations
A Phase 4 study testing mRNA-1283.251 Variant-containing Formulation in people with COVID-19, run by ModernaTX, Inc. at 5 sites in United States.
Trial summary
The purpose of this study is to evaluate the immunogenicity and safety of the recommended variant-containing formulations of mRNA-1283 COVID-19 vaccine (mNEXSPIKE®) within the current epidemiological environment. Read more about this study
- Who is it for?
- Ages 12 years and olderHealthy volunteers can take part
- Conditions the study is for
- COVID-19
- What is being tested?
- mRNA-1283.251 Variant-containing Formulation
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 832 participants
- Where
- 5 sitesUnited States
- Study dates
- 21 Jul 2025to 16 Jun 2026
- Phase
- Phase 4
- Are there results?
- None posted in the registry
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 12 years and older
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Who may be able to join
- Subprotocol 1:
- ≥65 years of age at the time of signing the informed consent or ≥12 to <65 years of age at the time of signing the informed consent with at least 1 risk factor for severe outcomes from COVID-19.
- Investigator's assessment that the participant understands and is willing and physically able to comply with protocol-mandated follow-up, including all procedures.
- Participants who are assigned female at birth or could become pregnant:
- Has a negative pregnancy test at the Screening Visit and on the day of vaccination prior to vaccine dose being administered on Day 1.
- Has practiced adequate contraception or has abstained from all activities that could result in pregnancy for at least 28 days prior to the first dose (Day 1).
- Has agreed to continue adequate contraception through 28 days following vaccine administration.
Who cannot join
- Subprotocol 1:
- History of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection within 6 months prior to enrollment.
- Acutely ill or febrile (temperature ≥38.0°Celsius/≥100.4°Fahrenheit) within 72 hours prior to or at the Screening Visit or Day 1. Participants meeting this criterion may be rescheduled within the Screening window and will retain their initially assigned participant number.
- History of a diagnosis or condition that, in the judgment of the Investigator, is clinically unstable or may affect participant safety, assessment of study endpoints, assessment of immune response, or adherence to study procedures.
- Receipt of the COVID-19 vaccine within 6 months prior to enrollment.
- Receipt of 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.
Show all 11Show fewer
- Receipt of systemic immunosuppressants for >14 days in total, within 180 days prior to Screening Visit (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.
- Receipt of systemic immunoglobulins, long-acting biological therapies that affect immune responses (for example, infliximab) or blood products within 90 days prior to the Screening Visit or plans to receive them during the study.
- History of anaphylaxis or severe hypersensitivity reaction requiring medical intervention after receipt of any mRNA vaccine or therapeutic or any components of an mRNA vaccine or therapeutic.
- Has donated ≥450 milliliters (mL) of blood products within 28 days prior to the Screening Visit or plans to donate blood products within 28 days after the study injection.
- Note: Other protocol-specified inclusion and exclusion criteria may apply.
Trial locations and contacts
5 sites in 1 country.
5 sites in 1 country
United States5 sites
DelRicht Research-Atlanta
Atlanta, Georgia, 30329
DelRicht Research-Baton Rouge
Baton Rouge, Louisiana, 70769
DelRicht Research-Gulfport
Gulfport, Mississippi, 39503
DelRicht Research-New Orleans
New Orleans, Louisiana, 70115
DelRicht Research-Tulsa
Tulsa, Oklahoma, 74133
About this study
Official title: A Phase 3b/4, Open-label Study to Evaluate the Immunogenicity and Safety of mRNA-1283 COVID-19 Variant-containing Vaccine Formulations
The purpose of this study is to evaluate the immunogenicity and safety of the recommended variant-containing formulations of mRNA-1283 COVID-19 vaccine (mNEXSPIKE®) within the current epidemiological environment.
Read the detailed description
This study uses a master protocol with a generic study design to allow flexibility in evaluating immunogenicity of variant-containing formulations of the mRNA-1283 COVID-19 vaccine. As different variant-containing vaccine formulations will be evaluated, each study intervention (for example, updated mRNA-1283 COVID-19 vaccine) will be described in the subprotocol. For each evaluation of an updated variant vaccine, a new subprotocol will be generated.
Subprotocol 01 is a single arm study to evaluate immunogenicity and safety of mRNA-1283 (COVID-19 vaccine) 2025-2026 formula in individuals aged ≥65 years and ≥12 to <65 years with at least 1 underlying condition that puts them at high risk for severe outcomes from COVID-19.
The study included Parts A and B. Part A enrollment was discontinued due to addition of Part B to evaluate the safety and immunogenicity of variant-containing mRNA-1283 using a hypothesis driven study endpoint with reactogenicity data collection and longer safety follow up in Part B.
- Conditions
- COVID-19
- Being tested
- mRNA-1283.251 Variant-containing Formulation
- Keywords
- mRNA-1283, mRNA-1283 vaccine, SARS-CoV-2, SARS-CoV-2 Vaccine, Coronavirus, Coronavirus Infections, Virus Diseases, mNEXSPIKE®, COVID-19, COVID-19 vaccine, Moderna
- Medical subject headings
- COVID-19, Coronavirus Infections, Virus Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
mRNA-1283.251 Variant-containing FormulationBiological
Also called mNEXSPIKE®
Sterile liquid for injection
| Study group | Role | What they receive |
|---|---|---|
| mRNA-1283.251 Variant-containing Formulation | Experimental | Participants will receive an intramuscular (IM) injection of a mRNA-1283.251 variant-containing formulation. Receives: Biological: mRNA-1283.251 Variant-containing Formulation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Subprotocol 1: Part A - Geometric Mean (GM) Value of Neutralizing Antibody (nAb) Against Vaccine-matched COVID-19 Variants
Measured: Day 29
Subprotocol 1: Part A - Geometric Mean Fold Rise (GMFR) of nAb Against Vaccine-matched COVID-19 Variants
Measured: Baseline to Day 29
Subprotocol 1: Part B - GMFR of nAb Against Vaccine-matched COVID-19 Variants
Measured: Baseline to Day 29
Subprotocol 1: Part A - Seroresponse Rate (SRR) of nAb Against Vaccine-matched COVID-19 Variants
Measured: Baseline to Day 29
Secondary outcomes (5)
Subprotocol 1: Part A - Number of Participants with Unsolicited Adverse Events (AEs), Serious Adverse Events (SAEs), AEs of Special Interests (AESIs), and AEs Leading to Study Withdrawal
Measured: Day 1 through Day 29
Subprotocol 1: Part B - Number of Participants with Unsolicited AEs
Measured: Day 1 through Day 29
Subprotocol 1: Part B - Number of Participants with SAEs, AESIs, and AEs Leading to Study Withdrawal
Measured: Day 1 through Day 181
Subprotocol 1: Part B - Geometric Mean Ratio (GMR) of nAb Against Vaccine-matched COVID-19 Variants Between Participants Aged ≥12 to <65 Years and Those Aged ≥65 Years
Measured: Day 29
Subprotocol 1: Part B - Number of Participants With Solicited Local and Systemic Adverse Reactions (ARs)
Measured: 7 days post vaccination
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Jul 2025
- Study start21 Jul 2025
- Primary completion16 Jun 2026
- Study completion16 Jun 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for COVID-19Studies 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 4
- Primary purpose
- Prevention
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- This is a Phase 3b/4 open-label study.
- Masking
- None (open label)
- Enrolment
- 832 participants (actual)
Sponsor and investigators
- Lead sponsor
- ModernaTX, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07089706
- Sponsor's protocol ID
- mRNA-1283-P401
- Status last verified
- Jun 2026
- First submitted
- 21 Jul 2025
- Last updated
- 7 Jul 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 7 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 3b/4, Open-label Study to Evaluate the Immunogenicity and Safety of mRNA-1283 COVID-19 Variant-containing Vaccine Formulations
- ClinicalTrials.gov ID
- NCT07089706
- Acronym / sponsor ID
- mRNA-1283-P401
- Conditions
- COVID-19
- Keywords
- mRNA-1283, mRNA-1283 vaccine, SARS-CoV-2, SARS-CoV-2 Vaccine, Coronavirus, Coronavirus Infections, Virus Diseases, mNEXSPIKE®
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 832 participants (actual)
- Lead sponsor
- ModernaTX, Inc.Industry (pharma, biotech, devices)
- Study start
- 21 Jul 2025 (actual)
- Primary completion
- 16 Jun 2026 (actual)
- Study completion
- 16 Jun 2026 (actual)
- First posted
- 28 Jul 2025 (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.
The purpose of this study is to evaluate the immunogenicity and safety of the recommended variant-containing formulations of mRNA-1283 COVID-19 vaccine (mNEXSPIKE®) within the current epidemiological environment.
Detailed description
This study uses a master protocol with a generic study design to allow flexibility in evaluating immunogenicity of variant-containing formulations of the mRNA-1283 COVID-19 vaccine. As different variant-containing vaccine formulations will be evaluated, each study intervention (for example, updated mRNA-1283 COVID-19 vaccine) will be described in the subprotocol. For each evaluation of an updated variant vaccine, a new subprotocol will be generated.
Subprotocol 01 is a single arm study to evaluate immunogenicity and safety of mRNA-1283 (COVID-19 vaccine) 2025-2026 formula in individuals aged ≥65 years and ≥12 to <65 years with at least 1 underlying condition that puts them at high risk for severe outcomes from COVID-19.
The study included Parts A and B. Part A enrollment was discontinued due to addition of Part B to evaluate the safety and immunogenicity of variant-containing mRNA-1283 using a hypothesis driven study endpoint with reactogenicity data collection and longer safety follow up in Part B.
Study design
- Primary purpose
- Prevention
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- This is a Phase 3b/4 open-label study.
| Arm | Type | Receives |
|---|---|---|
| mRNA-1283.251 Variant-containing Formulation | Experimental | Biological: mRNA-1283.251 Variant-containing FormulationParticipants will receive an intramuscular (IM) injection of a mRNA-1283.251 variant-containing formulation. |
Who may qualify
- Ages
- 12 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (7 listed)
- ≥65 years of age at the time of signing the informed consent or ≥12 to <65 years of age at the time of signing the informed consent with at least 1 risk factor for severe outcomes from COVID-19.
- Investigator's assessment that the participant understands and is willing and physically able to comply with protocol-mandated follow-up, including all procedures.
- Participants who are assigned female at birth or could become pregnant:
- Has practiced adequate contraception or has abstained from all activities that could result in pregnancy for at least 28 days prior to the first dose (Day 1).
- Has agreed to continue adequate contraception through 28 days following vaccine administration.
Key exclusion criteria (11 listed)
- History of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection within 6 months prior to enrollment.
- Acutely ill or febrile (temperature ≥38.0°Celsius/≥100.4°Fahrenheit) within 72 hours prior to or at the Screening Visit or Day 1. Participants meeting this criterion may be rescheduled within the Screening window and will retain their initially assigned participant number.
- History of a diagnosis or condition that, in the judgment of the Investigator, is clinically unstable or may affect participant safety, assessment of study endpoints, assessment of immune response, or adherence to study procedures.
- Receipt of the COVID-19 vaccine within 6 months prior to enrollment.
- Receipt of 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.
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-1283.251 Variant-containing FormulationAlso: mNEXSPIKE®Sterile liquid for injection | Biological | mRNA-1283.251 Variant-containing Formulation |
Primary outcome
Subprotocol 1: Part A - Geometric Mean (GM) Value of Neutralizing Antibody (nAb) Against Vaccine-matched COVID-19 Variants
Time frame: Day 29
Subprotocol 1: Part A - Geometric Mean Fold Rise (GMFR) of nAb Against Vaccine-matched COVID-19 Variants
Time frame: Baseline to Day 29
Subprotocol 1: Part B - GMFR of nAb Against Vaccine-matched COVID-19 Variants
Time frame: Baseline to Day 29
Subprotocol 1: Part A - Seroresponse Rate (SRR) of nAb Against Vaccine-matched COVID-19 Variants
Time frame: Baseline to Day 29
5 secondary outcomes
Subprotocol 1: Part A - Number of Participants with Unsolicited Adverse Events (AEs), Serious Adverse Events (SAEs), AEs of Special Interests (AESIs), and AEs Leading to Study Withdrawal
Time frame: Day 1 through Day 29
Subprotocol 1: Part B - Number of Participants with Unsolicited AEs
Time frame: Day 1 through Day 29
Subprotocol 1: Part B - Number of Participants with SAEs, AESIs, and AEs Leading to Study Withdrawal
Time frame: Day 1 through Day 181
Subprotocol 1: Part B - Geometric Mean Ratio (GMR) of nAb Against Vaccine-matched COVID-19 Variants Between Participants Aged ≥12 to <65 Years and Those Aged ≥65 Years
Time frame: Day 29
Subprotocol 1: Part B - Number of Participants With Solicited Local and Systemic Adverse Reactions (ARs)
Time frame: 7 days post vaccination
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Jul 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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
5 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing mRNA-1283.251 Variant-containing Formulation in people with COVID-19, run by ModernaTX, Inc. at 5 sites in United States.
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 7 inclusion and 11 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: finished, as of the sponsor's last update on 7 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 5 sites in United States. 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 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Subprotocol 1: Part A - Geometric Mean (GM) Value of Neutralizing Antibody (nAb) Against Vaccine-matched COVID-19 Variants (time frame: Day 29). The study lists 4 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 7 Jul 2026.