CompletedPhase 1/2

A Study About Modified RNA Vaccines Against Influenza in Healthy Adults

United States1,202 participantsStarted 2024-05-23

Plain-language summary

The purpose of this study is to learn if modified RNA (modRNA) vaccines for the prevention of influenza are: * safe; and * how these vaccines produce an immune response in generally healthy adults. Immune response is the way the body protects itself against things it sees as harmful or foreign. RNA (also called ribonucleic acid) is one of two types of nucleic acid made by cells. RNA contains information that has been copied from DNA (the other type of nucleic acid). Cells make several different forms of RNA, and each form has a specific job in the cell. Many forms of RNA have functions related to making proteins. RNA is also the genetic material of some viruses instead of DNA. RNA can be made in the laboratory and used in research studies. Also called ribonucleic acid. Influenza is term used for flu illness. It is an infection caused by a virus that affects your mouth, nose, and throat. The study is seeking for participants who: * are at least 18 years of age * have not received an influenza vaccine within the last 6 months * are generally healthy This study will be divided into three sub-studies: Substudy A (SSA), Substudy B (SSB), and Substudy C (SSC). All participants, regardless of sub-study, will receive 1 dose of either of the following vaccines as an injection into their arm: * 1 of the modRNA influenza vaccines that is being studied; or * an approved influenza vaccine approved for use in their respective age group. Participants will be involved in this study for about 6 months. During this time, participants will have at least 3 clinic visits.

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 Applies to all 3 substudies: * participants ≥18 years of age. * generally healthy participants. Substudy C ONLY: \- receipt of licensed influenza vaccination for the 2023-2024 flu season at least 6 months ago. Key Exclusion Criteria All 3 substudies: * diagnosis of influenza (by clinical testing) in the last 6 months. * immunocompromised individuals with known or suspected immunodeficiency * receipt of any investigational or licensed influenza vaccines within 6 months.

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

SSA: Percentage of Participants With Local Reactions for up to 7 Days Following Vaccination

Timeframe: From Day 1 through Day 7 after study vaccination [Vaccination on Day 1]

SSB: Percentage of Participants With Local Reactions for up to 7 Days Following Vaccination

Timeframe: From Day 1 through Day 7 after study vaccination [Vaccination on Day 1]

SSC: Percentage of Participants With Local Reactions for up to 7 Days Following Vaccination

Timeframe: From Day 1 through Day 7 after study vaccination [Vaccination on Day 1]

SSA: Percentage of Participants With Systemic Events for up to 7 Days Following Vaccination

Timeframe: From Day 1 through Day 7 after study vaccination [Vaccination on Day 1]

SSB: Percentage of Participants With Systemic Events for up to 7 Days Following Vaccination

Timeframe: From Day 1 through Day 7 after study vaccination [Vaccination on Day 1]

SSC: Percentage of Participants With Systemic Events for up to 7 Days Following Vaccination

Timeframe: From Day 1 through Day 7 after study vaccination [Vaccination on Day 1]

Trial details

NCT IDNCT06436703

SponsorPfizer

Sponsor typeINDUSTRY

Study typeINTERVENTIONAL

Primary completion2025-02-05

Results submitted2026-01-15

View on ClinicalTrials.gov More Influenza, Human trials