Only 656 spots left

~656 spots leftby Apr 2026

Modified RNA Vaccines for Flu

Recruiting at 31 trial locations

Overseen ByPfizer CT.gov Call Center

Age: 18+

Sex: Any

Travel: May Be Covered

Time Reimbursement: Varies

Trial Phase: Phase 2

Waitlist Available

Sponsor: Pfizer

No Placebo Group

Prior Safety Data

Trial Summary

What is the purpose of this trial?

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.

Research Team

Pfizer CT.gov Call Center

Principal Investigator

Pfizer

Eligibility Criteria

This trial is for generally healthy adults over 18 who haven't had a flu shot in the last 6 months. It's to see if new modRNA vaccines are safe and how they affect the body's defense against flu.

Inclusion Criteria

I am 18 years old or older.

Participants must be generally healthy

I received the flu shot for the 2023-2024 season over 6 months ago.

Exclusion Criteria

I was diagnosed with the flu in the last 6 months.

Immunocompromised individuals with known or suspected immunodeficiency

Receipt of any investigational or licensed influenza vaccines within 6 months

Treatment Details

Interventions

Influenza ModRNA Vaccine (Cancer Vaccine)

Trial OverviewThe study tests modified RNA (modRNA) vaccines against influenza, comparing them with an approved Quadrivalent Influenza Vaccine (QIV). Participants will be randomly assigned to receive one dose of either vaccine.

Participant Groups

19Treatment groups

Experimental Treatment

Active Control

Group I: SSC: Influenza ModRNA Vaccine 9CExperimental Treatment1 Intervention

- Single dose on Day 1

Group II: SSC: Influenza ModRNA Vaccine 8CExperimental Treatment1 Intervention

- Single Dose on Day 1

Group III: SSC: Influenza ModRNA Vaccine 7CExperimental Treatment1 Intervention

- Single Dose on Day 1

Group IV: SSC: Influenza ModRNA Vaccine 6CExperimental Treatment1 Intervention

- Single Dose on Day 1

Group V: SSC: Influenza ModRNA Vaccine 5CExperimental Treatment1 Intervention

- Single Dose on Day 1

Group VI: SSC: Influenza ModRNA Vaccine 4CExperimental Treatment1 Intervention

- Single Dose on Day 1

Group VII: SSC: Influenza ModRNA Vaccine 3CExperimental Treatment1 Intervention

- Single Dose on Day 1

Group VIII: SSB: Influenza ModRNA Vaccine 5BExperimental Treatment1 Intervention

- Single dose on Day 1

Group IX: SSB: Influenza ModRNA Vaccine 4BExperimental Treatment1 Intervention

- Single Dose on Day 1

Group X: SSB: Influenza ModRNA Vaccine 3BExperimental Treatment1 Intervention

- Single Dose on Day 1

Group XI: SSA: Influenza ModRNA Vaccine 5AExperimental Treatment1 Intervention

- Single dose on Day 1

Group XII: SSA: Influenza ModRNA Vaccine 4AExperimental Treatment1 Intervention

- Single Dose on Day 1

Group XIII: SSA: Influenza ModRNA Vaccine 3AExperimental Treatment1 Intervention

- Single Dose on Day 1

Group XIV: SSA: Influenza ModRNA Vaccine 2AExperimental Treatment1 Intervention

- Single Dose on Day 1

Group XV: SSA: QIV1Active Control1 Intervention

- Single dose on Day 1

Group XVI: SSB: QIV3Active Control1 Intervention

- Single Dose on Day 1

Group XVII: SSB: QIV2Active Control1 Intervention

- Single Dose on Day 1

Group XVIII: SSC: QIV2Active Control1 Intervention

- Single Dose on Day 1

Group XIX: SSC: QIV3Active Control1 Intervention

- Single Dose on Day 1

Find a Clinic Near You

Who Is Running the Clinical Trial?

Pfizer

Lead Sponsor

Trials

4,712

Recruited

50,980,000+

Known For

Vaccine Innovations