A Study of mRNA-1018-H5 Pandemic Influenza Vaccine in Healthy Adults

April 2, 2026 updated by: ModernaTX, Inc.

A Phase 3, Randomized, Observer-blind, Placebo-controlled Study to Evaluate the Immunogenicity, Safety, and Reactogenicity of mRNA-1018-H5 Pandemic Influenza Vaccine in Adults ≥18 Years of Age

The purpose of this study is to evaluate humoral immunogenicity after 2 doses of mRNA-1018-H5, and to evaluate the safety and reactogenicity of mRNA-1018-H5 in adults ≥18 years of age.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

4000

Phase

  • Phase 3

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 Kingdom
    • Bristol (Unitary Authority)
      • Bristol, Bristol (Unitary Authority), United Kingdom, BS8 2RA
        • Not yet recruiting
        • Velocity Clinical Research-Bristol
    • Buckinghamshire
      • High Wycombe, Buckinghamshire, United Kingdom, HP11 2QW
        • Not yet recruiting
        • Velocity Clinical Research - High Wycombe
    • Cambridgeshire
      • Peterborough, Cambridgeshire, United Kingdom, PE8 6PL
        • Not yet recruiting
        • Wansford Research LTD
    • County Durham
      • Stockton-on-Tees, County Durham, United Kingdom, TS19 8PE
        • Not yet recruiting
        • Futuremeds Teesside Middlefield Centre University Hospital of North Tees
    • Dorset
      • Bournemouth, Dorset, United Kingdom, BH7 7DW
        • Not yet recruiting
        • NIHR Wessex CRDC - Bournemouth Research Hub (Under University Hospital Southampton NHS Foundation Trust)
      • Weymouth, Dorset, United Kingdom, DT4 0QE
        • Not yet recruiting
        • NIHR Wessex CRDC - Weymouth Research Hub (Under University Hospital Southampton NHS Foundation Trust)
    • Glasgow City (Scotland)
      • Glasgow, Glasgow City (Scotland), United Kingdom, G51 4TF
        • Not yet recruiting
        • Panthera Glasgow
    • Greater London
      • Enfield, Greater London, United Kingdom, EN3 4GS
        • Not yet recruiting
        • Panthera Enfield
      • Hounslow, Greater London, United Kingdom, TW3 3ET
        • Not yet recruiting
        • Hounslow Medical Centre
      • London, Greater London, United Kingdom, E1 1EQ
        • Not yet recruiting
        • hVIVO Services Limited
      • London, Greater London, United Kingdom, N12 8BU
        • Not yet recruiting
        • Velocity Clinical Research-North London
      • Northwood, Greater London, United Kingdom, HA6 2RN
        • Not yet recruiting
        • Accellacare North London
      • Orpington, Greater London, United Kingdom, BR5 3QG
        • Not yet recruiting
        • Accellacare South London
      • Romford, Greater London, United Kingdom, RM1 3PJ
        • Not yet recruiting
        • Velocity Clinical Research-Romford
    • Greater Manchester
      • Rochdale, Greater Manchester, United Kingdom, OL11 4AU
        • Not yet recruiting
        • Panthera Rochdale
    • Hampshire
      • Southampton, Hampshire, United Kingdom, SO15 3UA
        • Not yet recruiting
        • NIHR Wessex CRDC - Southampton Research Hub (Under University Hospital Southampton NHS FT)
    • Lancashire
      • Blackpool, Lancashire, United Kingdom, FY3 7EN
        • Not yet recruiting
        • Fylde Coast Clinical Research at Layton Medical Centre
    • Merseyside
      • Metropolitan Borough of Wirral, Merseyside, United Kingdom, CH62 6EE
        • Not yet recruiting
        • FutureMeds Liverpool
    • North Northamptonshire
      • Corby, North Northamptonshire, United Kingdom, NN17 2UR
        • Not yet recruiting
        • Lakeside Healthcare
    • North Yorkshire
      • York, North Yorkshire, United Kingdom, YO24 4LJ
        • Not yet recruiting
        • Panthera York
    • Nottinghamshire
      • Nottingham, Nottinghamshire, United Kingdom, NG7 2QW
        • Not yet recruiting
        • The University of Nottingham Health Service
    • South Yorkshire
      • Sheffield, South Yorkshire, United Kingdom, S2 5FX
        • Not yet recruiting
        • Panthera Sheffield
    • Tyne and Wear
      • Newcastle upon Tyne, Tyne and Wear, United Kingdom, NE61SG
        • Not yet recruiting
        • FutureMeds Newcastle
    • West Midlands
      • Birmingham, West Midlands, United Kingdom, B21 9RY
        • Not yet recruiting
        • FutureMeds Birmingham Soho Road Health Centre
    • West Midlands (Coventry)
      • Coventry, West Midlands (Coventry), United Kingdom, CV3 4FJ
        • Not yet recruiting
        • Accellacare Warwickshire
    • West Yorkshire
      • Shipley, West Yorkshire, United Kingdom, BD18 3SA
        • Not yet recruiting
        • Accellacare Yorkshire
  • United States
    • California
      • San Bernardino, California, United States, 92408
        • Not yet recruiting
        • Velocity Clinical Research, San Bernardino
    • Georgia
      • Savannah, Georgia, United States, 31406
        • Not yet recruiting
        • Velocity Clinical Research, Savannah
    • Idaho
      • Meridian, Idaho, United States, 83642
        • Not yet recruiting
        • Velocity Clinical Research, Boise
    • Maryland
      • Rockville, Maryland, United States, 20854
        • Not yet recruiting
        • Velocity Clinical Research, Rockville
    • Nebraska
      • Omaha, Nebraska, United States, 68134
        • Not yet recruiting
        • Velocity Clinical Research, Omaha
    • Ohio
      • Beachwood, Ohio, United States, 44122
        • Recruiting
        • Velocity Clinical Research, Cleveland
    • Rhode Island
      • East Greenwich, Rhode Island, United States, 02818
        • Recruiting
        • Velocity Clinical Research, Providence
    • South Carolina
      • Anderson, South Carolina, United States, 29621
        • Not yet recruiting
        • Velocity Clinical Research, Anderson
    • Texas
      • Dallas, Texas, United States, 75230
        • Recruiting
        • Velocity Clinical Research, Dallas
    • Virginia
      • Suffolk, Virginia, United States, 23435
        • Not yet recruiting
        • Velocity Clinical Research, Suffolk

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
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Key Inclusion Criteria:

  • Healthy as determined by medical evaluation including medical history; and physical examination. Participants with clinically stable chronic medical conditions are permitted.

  • Participants who are assigned female at birth or could become pregnant are eligible to participate if the participant is not pregnant or breast/chest feeding, and one of the following conditions applies:

    • Is a person of nonchildbearing potential (PONCBP) OR
    • Is a person of childbearing potential (POCBP)
    • A POCBP must have a negative highly sensitive pregnancy test at Screening and on the day of the first dose of study intervention.

Key Exclusion Criteria:

  • Participant is acutely ill or febrile (body temperature ≥ 38.0 degrees Celsius [°C]/100.4 degrees Fahrenheit [°F]) within 72 hours prior to or at the Screening Visit or Day 1.
  • History of myocarditis, pericarditis, or myopericarditis.
  • History of Guillain-Barre syndrome.
  • Reported history of congenital or acquired immunodeficiency, immunosuppressive condition, asplenia, or recurrent severe infections disease.
  • Treated with antiviral therapies for influenza (eg, Tamiflu, Xofluza) within 28 days prior to Day 1.
  • Prior receipt of a pandemic influenza vaccine or participation in any pandemic influenza vaccine clinical study, including the mRNA-1018-P101 study.
  • Any medical, psychiatric, or occupational condition, that, in the opinion of the Investigator, might pose additional risk due to participation in the study or could interfere with adherence to study procedures or the interpretation of study results.
  • Participant has received systemic immunosuppressants including long-acting biological therapies that affect immune responses (eg, infliximab, methotrexate, omalizumab, etc.), within 180 days prior to Screening or plans to do so at any time during participation in the study.
  • Participant has received corticosteroids at ≥10 mg/day of prednisone or equivalent for >14 days in total within 90 days prior to Day 1 (Baseline) or is anticipating the need for corticosteroids at any time during the study.
  • Participants has received any licensed vaccine authorized or approved by local health agency including mRNA vaccine ≤28 days prior to study intervention (Day 1) or plans to receive a vaccine authorized or approved by local health agency within 21 days after the study intervention.
  • Participant has participated in an interventional clinical study within 90 days prior to the Screening visit based on the medical history interview or plans to do so while participating in this study.

Note: Other inclusion/exclusion criteria may apply.

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-1018-H5 Vaccine
Participants will receive mRNA-1018-H5 vaccine by intramuscular (IM) injection on Day 1 and Day 22.
Biological: mRNA-1018-H5
Sterile liquid for injection.
Placebo Comparator: Placebo
Participants will receive placebo matched to mRNA-1018-H5 vaccine by IM injection on Day 1 and Day 22.
Biological: Placebo
Sterile liquid for injection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs)
Time Frame: Up to Day 29 (7 days after each injection)
Up to Day 29 (7 days after each injection)
Percentage of Participants With Hemagglutination Inhibition (HAI) Titer ≥ 1:40 at Day 43
Time Frame: Day 43
HAI Titer >=1:40.
Day 43
Percentage of Participants With Seroconversion at Day 43, as Measured by HAI Assay
Time Frame: Day 43
Seroconversion is defined as a Day 43 titer ≥1:40 if baseline is <1:10 or a 4-fold or greater rise if baseline is ≥1:10 in HAI titer measured by HAI assay.
Day 43
Number of Participants with Unsolicited Adverse Events (AEs)
Time Frame: Up to Day 50 (28 days after each injection)
Up to Day 50 (28 days after each injection)
Number of Participants with AEs Leading to Discontinuation, Medically-attended AEs (MAAEs), Serious Adverse Events (SAEs), Adverse Events of Special Interest (AESIs)
Time Frame: Day 1 to Day 205
Day 1 to Day 205

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Geometric Mean Titer (GMT) of Anti-H5N1 Antibodies at Day 43, as Measured by Microneutralization (MN) Assay
Time Frame: Day 43
Day 43
GMT of HAI Antibodies at Days 22 and 205, as Measured by HAI Assay
Time Frame: Days 22 and 205
Days 22 and 205
GMT of HAI Antibodies at Days 22 and 205, as Measured by MN Assay
Time Frame: Days 22 and 205
Days 22 and 205
Percentage of Participants with HAI Titers at Different Cut-Offs
Time Frame: Up to Day 205
Cutoff included >= 1:80.
Up to Day 205

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)

March 23, 2026

Primary Completion (Estimated)

January 28, 2027

Study Completion (Estimated)

January 28, 2027

Study Registration Dates

First Submitted

March 22, 2026

First Submitted That Met QC Criteria

March 22, 2026

First Posted (Actual)

March 27, 2026

Study Record Updates

Last Update Posted (Actual)

April 3, 2026

Last Update Submitted That Met QC Criteria

April 2, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • mRNA-1018-P301

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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