A Study of Updated mRNA Seasonal Influenza Vaccines

November 12, 2026 updated by: ModernaTX, Inc.

A Phase 3b/4 Study to Assess the Immunogenicity and Safety of Updated mRNA Seasonal Influenza Vaccine Compositions

The purpose of this study is to evaluate the immunogenicity and safety of updated strain-containing compositions of the mRNA-1010 vaccines within the current epidemiological environment.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This study uses a master protocol with a generic study design to allow flexibility in evaluating immunogenicity and safety of updated strain-containing compositions of the mRNA-1010 vaccines. As different strain-containing vaccine compositions will be evaluated, each study intervention will be described in the subprotocol. For each evaluation of an updated strain, a new subprotocol will be generated. Reported outcome measures are based upon each subprotocol. Not all reported outcome measures may be applicable to each subprotocol.

Subprotocol 01 is to evaluate the 2026-2027 mRNA influenza vaccine.

Study Type

Interventional

Enrollment (Estimated)

200

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 Contact

Study Locations

  • United States
    • Arizona
      • Tucson, Arizona, United States, 85711
        • Recruiting
        • Arizona Clinical Trials
    • Kansas
      • Lenexa, Kansas, United States, 66219
        • Recruiting
        • Johnson County Clin-Trials LLC (JCCT)
    • Kentucky
      • Louisville, Kentucky, United States, 40205
        • Recruiting
        • DelRicht Research at Derby City Direct Primary Care
    • Missouri
      • Town and Country, Missouri, United States, 63017
        • Recruiting
        • DelRicht Research at Amy Roberts MD and Associates

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

65 years and older (Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Key Inclusion Criteria:

  • Capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in the protocol.
  • Female participants must be of non-childbearing potential.

Key Exclusion Criteria:

  • Acutely ill or febrile (temperature ≥38.0 degrees Celsius (℃) [100.4° Fahrenheit [F]]) within 72 hours prior to at the Screening Visit or Day 1.
  • 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
  • History of a diagnosis or condition that, in the judgment of the Investigator, is clinically unstable, potentially affects participant safety, could interfere with interpretation of study results or limit the participant's participation in the study.
  • History of myocarditis, pericarditis, or myopericarditis within 90 days prior to Day 1 (Baseline).
  • Received corticosteroids at ≥10 mg/day of prednisone or equivalent for >14 days in total within 90 days prior to Day 1 (Baseline) or within 28 days after Day 1.
  • Received systemic immunosuppressive treatment, including long-acting biological therapies that affect immune responses (eg, infliximab), within 180 days prior to Day 1 (Baseline) or plans to do so during the study.
  • Tested positive for influenza by US Centers for Disease Control and Prevention (CDC)-recommended testing methods within 180 days prior to Day 1.
  • Received systemic immunoglobulins or blood products within 90 days prior to Day 1 (Baseline) or plans to do so during the study.
  • Received any vaccine (excluding seasonal influenza vaccine) authorized or approved by local health agency within 28 days prior to Day 1 (Baseline) or plans to do so within 14 days after Day 1 (Baseline).
  • Received a licensed or investigational seasonal influenza vaccine within 6 months prior to Day 1 (Baseline) or plans to do so (outside of this study) at any time during the study.

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-1010 Influenza Strain-containing Composition (2026- 2027)

Participants will receive a single dose of mRNA-1010 by intramuscular (IM) injection on Day 1.
Biological: mRNA-1010

Sterile liquid for injection
Active Comparator: Licensed High-Dose Seasonal Influenza Vaccine

Participants will receive a single dose of licensed high-dose seasonal influenza vaccine by IM injection on Day 1.
Biological: Licensed High-Dose Seasonal Influenza Vaccine

Sterile liquid for injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Geometric Mean Titer (GMT) of Anti-Hemagglutinin (HA) Antibodies at Day 29, as Measured by Hemagglutination Inhibition (HAI) Assay
Time Frame: Day 29
Day 29
Number of Participants Reaching Seroconversion at Day 29 as Measured by HAI Assay
Time Frame: Day 29

Seroconversion is defined as a Day 29 titer ≥1:40 if baseline is <1:10 or a 4-fold or greater rise if baseline is ≥1:10 in anti-HA antibodies measured by HAI assay.
Day 29
Number of Participants with an HAI Titer ≥1:40 at Day 29
Time Frame: Day 29
Day 29
Geometric Mean Fold Rise (GMFR), as Measured by HAI Assay
Time Frame: Baseline to Day 29
Baseline to Day 29

Secondary Outcome Measures

Outcome Measure
Time Frame
Number of Participants with Unsolicited Adverse Events (AEs)
Time Frame: Day 1 through Day 29
Day 1 through Day 29
Number of Participants with Serious AEs, Medical-attended AEs and AE of Interest, and AEs Leading to Discontinuation
Time Frame: Day 1 through Day 29
Day 1 through Day 29

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)

October 15, 2026

Primary Completion (Estimated)

December 7, 2026

Study Completion (Estimated)

December 7, 2026

Study Registration Dates

First Submitted

October 13, 2026

First Submitted That Met QC Criteria

October 13, 2026

First Posted (Actual)

October 20, 2026

Study Record Updates

Last Update Posted (Actual)

November 13, 2026

Last Update Submitted That Met QC Criteria

November 12, 2026

Last Verified

November 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • mRNA-1010-P401

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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