RecruitingPhase 3

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

United States, United Kingdom4,000 participantsStarted 2026-03-23

Plain-language summary

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.

Who can participate

Age range

18 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

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 …

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Percentage of Participants With Hemagglutination Inhibition (HAI) Titer ≥ 1:40 at Day 43

Timeframe: Day 43

Percentage of Participants With Seroconversion at Day 43, as Measured by HAI Assay

Timeframe: Day 43

Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs)

Timeframe: Up to Day 29 (7 days after each injection)

Number of Participants with Unsolicited Adverse Events (AEs)

Timeframe: 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)

Timeframe: Day 1 to Day 205

Trial details

NCT IDNCT07496450

SponsorModernaTX, Inc.

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2027-01-28

Contact for this trial

Moderna WeCare Team

1-866-663-3762 WeCareClinicalTrials@modernatx.com

View on ClinicalTrials.gov More Influenza trials

Who can participate

Age range

18 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

What they're measuring

Percentage of Participants With Hemagglutination Inhibition (HAI) Titer ≥ 1:40 at Day 43

Timeframe: Day 43

Percentage of Participants With Seroconversion at Day 43, as Measured by HAI Assay

Timeframe: Day 43

Number of Participants with Solicited Local and Systemic Adverse Reactions (ARs)

Timeframe: Up to Day 29 (7 days after each injection)

Number of Participants with Unsolicited Adverse Events (AEs)

Timeframe: 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)

Timeframe: Day 1 to Day 205