NCT06436703

Brief 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.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
1,202

participants targeted

Target at P75+ for phase_1

Timeline
Completed

Started May 2024

Geographic Reach
1 country

32 active sites

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

May 23, 2024

Completed
1 day until next milestone

First Submitted

Initial submission to the registry

May 24, 2024

Completed
7 days until next milestone

First Posted

Study publicly available on registry

May 31, 2024

Completed
8 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

February 5, 2025

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

February 5, 2025

Completed
1.3 years until next milestone

Results Posted

Study results publicly available

June 12, 2026

Completed
Last Updated

June 12, 2026

Status Verified

June 1, 2026

Enrollment Period

9 months

First QC Date

May 24, 2024

Results QC Date

January 15, 2026

Last Update Submit

June 9, 2026

Conditions

Outcome Measures

Primary Outcomes (18)

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

    Local reactions included pain at the injection site, redness and swelling and were recorded by participants in the electronic dairy (e-diary) or by investigators in case report form (CRF) after vaccination. All local reactions were graded based on center for biologics evaluation and research (CBER) toxicity guidelines as Grade 1 (Mild), Grade 2 (Moderate), Grade 3 (Severe) and Grade 4 (potentially life-threatening). In this outcome measure, data is reported as percentage of participants with any local reaction of any grade.

    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

    Local reactions included pain at the injection site, redness and swelling and were recorded by participants in the e-diary or by investigators in CRF after vaccination. All local reactions were graded based on CBER toxicity guidelines as Grade 1 (Mild), Grade 2 (Moderate), Grade 3 (Severe) and Grade 4 (potentially life-threatening). In this outcome measure, data is reported as percentage of participants with any local reaction of any grade.

    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

    Local reactions included pain at the injection site, redness and swelling and were recorded by participants in the e-diary or by investigators in CRF after vaccination. All local reactions were graded based on CBER toxicity guidelines as Grade 1 (Mild), Grade 2 (Moderate), Grade 3 (Severe) and Grade 4 (potentially life-threatening). In this outcome measure, data is reported as percentage of participants with any local reaction of any grade.

    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

    Systemic events (fever, vomiting, diarrhea, headache, fatigue, chills, new or worsened muscle pain and joint pain) were recorded by participants in the e-diary or by investigators in CRF after vaccination. All systemic events were graded based on CBER toxicity guidelines as Grade 1 (Mild), Grade 2 (Moderate), Grade 3 (Severe) and Grade 4 (potentially life-threatening). In this outcome measure, data is reported as percentage of participants with any systemic events of any grade.

    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

    Systemic events (fever, vomiting, diarrhea, headache, fatigue, chills, new or worsened muscle pain and joint pain) were recorded by participants in the e-diary or by investigators in CRF after vaccination. All systemic events were graded based on CBER toxicity guidelines as Grade 1 (Mild), Grade 2 (Moderate), Grade 3 (Severe) and Grade 4 (potentially life-threatening). In this outcome measure, data is reported as percentage of participants with any systemic events of any grade.

    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

    Systemic events (fever, vomiting, diarrhea, headache, fatigue, chills, new or worsened muscle pain and joint pain) were recorded by participants in the e-diary or by investigators in CRF after vaccination. All systemic events were graded based on CBER toxicity guidelines as Grade 1 (Mild), Grade 2 (Moderate), Grade 3 (Severe) and Grade 4 (potentially life-threatening). In this outcome measure, data is reported as percentage of participants with any systemic events of any grade.

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

  • SSA: Percentage of Participants With Adverse Events (AEs) From Vaccination Through 4 Weeks After Vaccination

    An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Only AEs collected by non-systematic assessment (excluding local reactions and systematic events) were included in this outcome measure.

    From study vaccination on Day 1 through 4 weeks after study vaccination

  • SSB: Percentage of Participants With AEs From Vaccination Through 4 Weeks After Vaccination

    An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Only AEs collected by non-systematic assessment (excluding local reactions and systematic events) were included in this outcome measure.

    From study vaccination on Day 1 through 4 weeks after study vaccination

  • SSC: Percentage of Participants With AEs From Vaccination Through 4 Weeks After Vaccination

    An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Only AEs collected by non-systematic assessment (excluding local reactions and systematic events) were included in this outcome measure.

    From study vaccination on Day 1 through 4 weeks after study vaccination

  • SSA: Percentage of Participants With SAEs From Vaccination Through 6 Months After Vaccination

    An SAE was defined as any untoward medical occurrence that, at any dose, met one or more of the following criteria: resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, any other pre-specified criteria in protocol of the study or other important medical event judged by the investigator.

    From study vaccination on Day 1 through 6 months after study vaccination

  • SSB: Percentage of Participants With SAEs From Vaccination Through 6 Months After Vaccination

    An SAE was defined as any untoward medical occurrence that, at any dose, met one or more of the following criteria: resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, any other pre-specified criteria in protocol of the study or other important medical event judged by the investigator.

    From study vaccination on Day 1 through 6 months after study vaccination

  • SSC: Percentage of Participants With SAEs From Vaccination Through 6 Months After Vaccination

    An SAE was defined as any untoward medical occurrence that, at any dose, met one or more of the following criteria: resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, any other pre-specified criteria in protocol of the study or other important medical event judged by the investigator.

    From study vaccination on Day 1 through 6 months after study vaccination

  • SSA: Percentage of Participants With Medically Attended Adverse Events (MAEs) From Vaccination Through 6 Months After Vaccination

    An MAE was defined as a non-serious AE that resulted in an evaluation at a medical facility.

    From study vaccination on Day 1 through 6 months after study vaccination

  • SSB: Percentage of Participants With MAEs From Vaccination Through 6 Months After Vaccination

    An MAE was defined as a non-serious AE that resulted in an evaluation at a medical facility.

    From study vaccination on Day 1 through 6 months after study vaccination

  • SSC: Percentage of Participants With MAEs From Vaccination Through 6 Months After Vaccination

    An MAE was defined as a non-serious AE that resulted in an evaluation at a medical facility.

    From study vaccination on Day 1 through 6 months after study vaccination

  • SSA: Percentage of Participants With Newly Diagnosed Chronic Medical Conditions (NDCMCs) From Vaccination Through 6 Months After Vaccination

    An NDCMC was defined as a disease or medical condition, not previously identified, that was expected to be persistent or otherwise long-lasting in its effects (e.g., asthma).

    From study vaccination on Day 1 through 6 months after study vaccination

  • SSB: Percentage of Participants With NDCMCs From Vaccination Through 6 Months After Vaccination

    An NDCMC was defined as a disease or medical condition, not previously identified, that was expected to be persistent or otherwise long-lasting in its effects (e.g., asthma).

    From study vaccination on Day 1 through 6 months after study vaccination

  • SSC: Percentage of Participants With NDCMCs From Vaccination Through 6 Months After Vaccination

    An NDCMC was defined as a disease or medical condition, not previously identified, that was expected to be persistent or otherwise long-lasting in its effects (e.g., asthma).

    From study vaccination on Day 1 through 6 months after study vaccination

Secondary Outcomes (8)

  • SSA: Geometric Mean Titers (GMTs) of Strain-Specific Hemagglutination Inhibition Assay (HAI) Titers at Baseline and 4 Weeks After Vaccination

    Baseline (before study vaccination on Day 1), 4 weeks after study vaccination

  • SSA: Geometric Mean Fold Rise (GMFR) of Strain-Specific HAI Titers From Before Vaccination to 4 Weeks After Vaccination

    From before study vaccination on Day 1 up to 4 weeks after study vaccination

  • SSA: Percentage of Participants Achieving HAI Seroconversion for Each Strain at 4 Weeks After Vaccination

    4 weeks after study vaccination

  • SSA: Percentage of Participants With HAI Titers >=1:40 For Each Strain at Baseline and 4 Weeks After Vaccination

    Baseline (before study vaccination on Day 1), 4 weeks after study vaccination

  • SSB: GMTs of Strain-Specific HAI Titers at Baseline and 4 Weeks After Vaccination

    Baseline (before study vaccination on Day 1), 4 weeks after study vaccination

  • +3 more secondary outcomes

Study Arms (19)

SSA: Influenza ModRNA Vaccine 2A

EXPERIMENTAL

\- Single Dose on Day 1

Biological: Influenza ModRNA Vaccine

SSA: Influenza ModRNA Vaccine 3A

EXPERIMENTAL

\- Single Dose on Day 1

Biological: Influenza ModRNA Vaccine

SSA: Influenza ModRNA Vaccine 4A

EXPERIMENTAL

\- Single Dose on Day 1

Biological: Influenza ModRNA Vaccine

SSA: Influenza ModRNA Vaccine 5A

EXPERIMENTAL

\- Single dose on Day 1

Biological: Influenza ModRNA Vaccine

SSA: QIV1

ACTIVE COMPARATOR

\- Single dose on Day 1

Biological: Quadrivalent Influenza Vaccine (QIV)

SSB: Influenza ModRNA Vaccine 3B

EXPERIMENTAL

\- Single Dose on Day 1

Biological: Influenza ModRNA Vaccine

SSB: Influenza ModRNA Vaccine 4B

EXPERIMENTAL

\- Single Dose on Day 1

Biological: Influenza ModRNA Vaccine

SSB: Influenza ModRNA Vaccine 5B

EXPERIMENTAL

\- Single dose on Day 1

Biological: Influenza ModRNA Vaccine

SSB: QIV2

ACTIVE COMPARATOR

\- Single Dose on Day 1

Biological: Quadrivalent Influenza Vaccine (QIV)

SSB: QIV3

ACTIVE COMPARATOR

\- Single Dose on Day 1

Biological: Quadrivalent Influenza Vaccine (QIV)

SSC: Influenza ModRNA Vaccine 3C

EXPERIMENTAL

\- Single Dose on Day 1

Biological: Influenza ModRNA Vaccine

SSC: Influenza ModRNA Vaccine 4C

EXPERIMENTAL

\- Single Dose on Day 1

Biological: Influenza ModRNA Vaccine

SSC: Influenza ModRNA Vaccine 5C

EXPERIMENTAL

\- Single Dose on Day 1

Biological: Influenza ModRNA Vaccine

SSC: Influenza ModRNA Vaccine 6C

EXPERIMENTAL

\- Single Dose on Day 1

Biological: Influenza ModRNA Vaccine

SSC: Influenza ModRNA Vaccine 7C

EXPERIMENTAL

\- Single Dose on Day 1

Biological: Influenza ModRNA Vaccine

SSC: Influenza ModRNA Vaccine 8C

EXPERIMENTAL

\- Single Dose on Day 1

Biological: Influenza ModRNA Vaccine

SSC: Influenza ModRNA Vaccine 9C

EXPERIMENTAL

\- Single dose on Day 1

Biological: Influenza ModRNA Vaccine

SSC: QIV2

ACTIVE COMPARATOR

\- Single Dose on Day 1

Biological: Quadrivalent Influenza Vaccine (QIV)

SSC: QIV3

ACTIVE COMPARATOR

\- Single Dose on Day 1

Biological: Quadrivalent Influenza Vaccine (QIV)

Interventions

Intramuscular injection

SSA: Influenza ModRNA Vaccine 2ASSA: Influenza ModRNA Vaccine 3ASSA: Influenza ModRNA Vaccine 4ASSA: Influenza ModRNA Vaccine 5ASSB: Influenza ModRNA Vaccine 3BSSB: Influenza ModRNA Vaccine 4BSSB: Influenza ModRNA Vaccine 5BSSC: Influenza ModRNA Vaccine 3CSSC: Influenza ModRNA Vaccine 4CSSC: Influenza ModRNA Vaccine 5CSSC: Influenza ModRNA Vaccine 6CSSC: Influenza ModRNA Vaccine 7CSSC: Influenza ModRNA Vaccine 8CSSC: Influenza ModRNA Vaccine 9C

Intramuscular injection

SSA: QIV1SSB: QIV2SSB: QIV3SSC: QIV2SSC: QIV3

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • 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.

You may not qualify if:

  • 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.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (32)

AMR Clinical

Mobile, Alabama, 36608, United States

Location

Headlands Research - Scottsdale

Scottsdale, Arizona, 85260, United States

Location

Anaheim Clinical Trials, LLC

Anaheim, California, 92801, United States

Location

Orange County Research Center

Lake Forest, California, 92630, United States

Location

Artemis Institute for Clinical Research

San Diego, California, 92103, United States

Location

Diablo Clinical Research, Inc.

Walnut Creek, California, 94598, United States

Location

Clinical Research Consulting

Milford, Connecticut, 06460, United States

Location

Indago Research & Health Center, Inc

Hialeah, Florida, 33012, United States

Location

Research Centers of America ( Hollywood )

Hollywood, Florida, 33024, United States

Location

Research Centers of America

Hollywood, Florida, 33024, United States

Location

Palm Springs Community Health Center

Miami Lakes, Florida, 33014, United States

Location

Clinical Neuroscience Solutions, Inc.

Orlando, Florida, 32801, United States

Location

Headlands Research Orlando

Orlando, Florida, 32819, United States

Location

Qps-Mra, Llc

South Miami, Florida, 33143, United States

Location

East-West Medical Research Institute

Honolulu, Hawaii, 96814, United States

Location

Alliance for Multispecialty Research, LLC

New Orleans, Louisiana, 70119, United States

Location

Prism Research LLC dba Nucleus Network

Saint Paul, Minnesota, 55114, United States

Location

Clinical Research Professionals

Chesterfield, Missouri, 63005, United States

Location

Alliance for Multispecialty Research, LLC

Kansas City, Missouri, 64114, United States

Location

Rochester Clinical Research, LLC

Rochester, New York, 14609, United States

Location

Duke Vaccine and Trials Unit

Durham, North Carolina, 27703, United States

Location

M3 Wake Research, Inc.

Raleigh, North Carolina, 27612, United States

Location

DM Clinical Research - Philadelphia

Philadelphia, Pennsylvania, 19107, United States

Location

Headlands Horizons LLC

Brownsville, Texas, 78526, United States

Location

SMS Clinical Research

Mesquite, Texas, 75149, United States

Location

Clinical Trials of Texas, LLC dba Flourish Research

San Antonio, Texas, 78229, United States

Location

Clinical Trials of Texas, LLC

San Antonio, Texas, 78229, United States

Location

Dynamed Clinical Research, LP d/b/a DM Clinical Research

Tomball, Texas, 77375, United States

Location

J. Lewis Research, Inc. / Foothill Family Clinic

Salt Lake City, Utah, 84109, United States

Location

J. Lewis Research, Inc. / Foothill Family Clinic South

Salt Lake City, Utah, 84121, United States

Location

Charlottesville Medical Research

Charlottesville, Virginia, 22911, United States

Location

AMR Clinical

Norfolk, Virginia, 23502, United States

Location

Related Links

MeSH Terms

Conditions

Influenza, Human

Interventions

Influenza Vaccines

Condition Hierarchy (Ancestors)

Respiratory Tract InfectionsInfectionsOrthomyxoviridae InfectionsRNA Virus InfectionsVirus DiseasesRespiratory Tract Diseases

Intervention Hierarchy (Ancestors)

Viral VaccinesVaccinesBiological ProductsComplex Mixtures

Limitations and Caveats

As per Sponsor's decision information on formulation and dose has not been disclosed in the results summary to maintain the company confidentiality.

Results Point of Contact

Title
Pfizer ClinicalTrials.gov Call Center
Organization
Pfizer Inc.

Study Officials

  • Pfizer CT.gov Call Center

    Pfizer

    STUDY DIRECTOR

Publication Agreements

PI is Sponsor Employee
No
Restriction Type
OTHER
Restrictive Agreement
Yes

Study Design

Study Type
interventional
Phase
phase 1
Allocation
RANDOMIZED
Masking
QUADRUPLE
Who Masked
PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
Masking Details
This study will be an observer-blinded and Sponsor-unblinded study.
Purpose
PREVENTION
Intervention Model
PARALLEL
Sponsor Type
INDUSTRY
Responsible Party
SPONSOR

Study Record Dates

First Submitted

May 24, 2024

First Posted

May 31, 2024

Study Start

May 23, 2024

Primary Completion

February 5, 2025

Study Completion

February 5, 2025

Last Updated

June 12, 2026

Results First Posted

June 12, 2026

Record last verified: 2026-06

Data Sharing

IPD Sharing
Will share

Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.

More information

Locations