A Study to Evaluate a Modified RNA Vaccine Against Influenza in Adults 18 Years of Age or Older
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ClinicalTrials.gov Identifier: NCT05540522 |
Recruitment Status :
Recruiting
First Posted : September 14, 2022
Last Update Posted : May 30, 2023
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Condition or disease | Intervention/treatment | Phase |
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Influenza, Human | Biological: Quadrivalent influenza modRNA vaccine Biological: Quadrivalent influenza vaccine | Phase 3 |
This is a Phase 3, randomized, observer-blinded study to evaluate the efficacy, safety, tolerability, and immunogenicity of a quadrivalent influenza modRNA vaccine (qIRV) encoding HA of 4 seasonally recommended strains (2 A strains and 2 B strains) compared to licensed quadrivalent influenza vaccine (QIV) in healthy adults 18 years of age and older.
Participants may be enrolled in either the reactogenicity subset, immunogenicity subset, or both subsets. Efficacy will be assessed in this study through surveillance for influenza-like illness.
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 36200 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Masking Description: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Primary Purpose: | Prevention |
Official Title: | A PHASE 3, RANDOMIZED, OBSERVER-BLINDED STUDY TO EVALUATE THE EFFICACY, SAFETY, TOLERABILITY, AND IMMUNOGENICITY OF A MODIFIED RNA VACCINE AGAINST INFLUENZA COMPARED TO LICENSED INACTIVATED INFLUENZA VACCINE IN HEALTHY ADULTS 18 YEARS OF AGE OR OLDER |
Actual Study Start Date : | September 12, 2022 |
Estimated Primary Completion Date : | March 7, 2024 |
Estimated Study Completion Date : | March 7, 2024 |

Arm | Intervention/treatment |
---|---|
Experimental: Quadrivalent influenza modRNA vaccine, 18 through 64 years of age
Quadrivalent influenza modRNA vaccine (single dose), participants 18 through 64 years of age
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Biological: Quadrivalent influenza modRNA vaccine
Quadrivalent influenza modRNA vaccine (single dose) |
Active Comparator: Quadrivalent influenza vaccine, 18 through 64 years of age
Licensed quadrivalent influenza vaccine (single dose), participants 18 through 64 years of age
|
Biological: Quadrivalent influenza vaccine
Licensed quadrivalent influenza vaccine (single dose) |
Experimental: Quadrivalent influenza modRNA vaccine, ≥65 years of age
Quadrivalent influenza modRNA vaccine (single dose), participants ≥65 years of age
|
Biological: Quadrivalent influenza modRNA vaccine
Quadrivalent influenza modRNA vaccine (single dose) |
Active Comparator: Quadrivalent influenza vaccine, ≥65 years of age
Licensed quadrivalent influenza vaccine (single dose), participants ≥65 years of age
|
Biological: Quadrivalent influenza vaccine
Licensed quadrivalent influenza vaccine (single dose) |
- The proportion of participants reporting laboratory-confirmed influenza (LCI) cases with associated per-protocol influenza-like illness (ILI) in each vaccine group, 18 through 64 years of age and ≥65 years of age combined [ Time Frame: At least 14 days after vaccination ]As measured at the central laboratory
- Geometric mean ratio (GMR) of hemagglutination inhibition (HAI) titers for each strain in qIRV recipients compared to QIV recipients, 18 through 64 and ≥65 years of age separately [ Time Frame: 4 weeks after vaccination ]As measured at the central laboratory
- Difference in percentage of participants achieving seroconversion for each strain between qIRV recipients and QIV recipients, 18 through 64 and ≥65 years of age separately [ Time Frame: 4 weeks after vaccination ]As measured at the central laboratory
- Percentage of participants reporting local reactions, 18 through 64 years of age and ≥65 years of age separately and combined [ Time Frame: For up to 7 days following vaccination ]Pain at the injection site, redness, and swelling
- Percentage of participants reporting systemic events, 18 through 64 years of age and ≥65 years of age separately and combined [ Time Frame: For up to 7 days following vaccination ]Fever, fatigue, headache, chills, vomiting, diarrhea, new or worsened muscle pain, and new or worsened joint pain
- Percentage of participants reporting adverse events, 18 through 64 years of age and ≥65 years of age separately and combined [ Time Frame: From the time the participant provides informed consent through 4 weeks after vaccination ]As elicited by investigational site staff
- Percentage of participants reporting serious adverse events, 18 through 64 years of age and ≥65 years of age separately and combined [ Time Frame: From the time the participant provides informed consent through 6 months after vaccination ]As elicited by investigational site staff
- GMR of HAI titers for each A strain in qIRV recipients compared to QIV recipients, 18 through 64 years of age and ≥65 years of age separately [ Time Frame: 4 weeks after vaccination ]As measured at the central laboratory
- Difference in percentage achieving seroconversion for each A strain between qIRV recipients and QIV recipients, 18 through 64 and ≥65 years of age separately [ Time Frame: 4 weeks after vaccination ]As measured at the central laboratory
- HAI geometric mean titers (GMTs) for each strain, 18 through 64 years of age and ≥65 years of age separately [ Time Frame: At 4 weeks and 6 months after vaccination ]As measured at the central laboratory
- HAI geometric mean fold rise (GMFR) for each strain, 18 through 64 years of age and ≥65 years of age separately [ Time Frame: Before vaccination and at 4 weeks and 6 months after vaccination ]As measured at the central laboratory
- The proportion of participants achieving HAI seroconversion for each strain, 18 through 64 years of age and ≥65 years of age separately [ Time Frame: At 4 weeks and 6 months after vaccination ]As measured at the central laboratory
- The proportion of participants with HAI titers ≥1:40 for each strain, 18 through 64 years of age and ≥65 years of age separately [ Time Frame: Before vaccination and at 4 weeks and 6 months after vaccination ]As measured at the central laboratory
- The proportion of participants achieving HAI seroconversion for all strains, 18 through 64 years of age and ≥65 years of age separately [ Time Frame: At 4 weeks and 6 months after vaccination ]As measured at the central laboratory
- The proportion of participants with HAI titers ≥1:40 for all strains, 18 through 64 years of age and ≥65 years of age separately [ Time Frame: Before vaccination and at 4 weeks and 6 months after vaccination ]As measured at the central laboratory
- The proportion of participants reporting LCI cases with associated per-protocol ILI in each vaccine group, ≥65 years of age [ Time Frame: At least 14 days after vaccination ]As measured at the central laboratory
- The proportion of participants reporting LCI cases with associated per-protocol ILI in each vaccine group, 18 through 64 years of age [ Time Frame: At least 14 days after vaccination ]As measured at the central laboratory
- The proportion of participants reporting LCI cases with associated per-protocol ILI in each vaccine group, ≥18 years of age, by season [ Time Frame: At least 14 days after vaccination ]As measured at the central laboratory
- The proportion of participants reporting LCI cases with associated per-protocol ILI caused by all matched strains or each matched strain in each vaccine group, 18 through 64 years of age and ≥65 years of age separately and combined [ Time Frame: At least 14 days after vaccination ]As measured at the central laboratory
- The proportion of participants reporting culture-confirmed influenza (CCI) cases with associated per-protocol ILI in each vaccine group, 18 through 64 years of age and ≥65 years of age separately and combined [ Time Frame: At least 14 days after vaccination ]As measured at the central laboratory
- The proportion of participants reporting LCI associated with ILI, as defined by applying a modified CDC definition, in each vaccine group, 18 through 64 years of age and ≥65 years of age separately and combined [ Time Frame: At least 14 days after vaccination ]As measured at the central laboratory
- The proportion of participants reporting LCI cases associated with ILI, as defined by applying the WHO definition, in each vaccine group, 18 through 64 years of age and ≥65 years of age separately and combined [ Time Frame: At least 14 days after vaccination ]As measured at the central laboratory
- The proportion of participants reporting cases of influenza, as confirmed by local RT-PCR or culture, with associated per-protocol ILI in each vaccine group, 18 through 64 years of age and ≥65 years of age separately and combined [ Time Frame: At least 14 days after vaccination ]As measured at the central laboratory

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
- Male or female participants ≥18 years of age at Visit 1 (Day 1).
- Participants who are willing and able to comply with all scheduled visits, investigational plan, laboratory tests, lifestyle considerations, and other study procedures.
- Healthy participants who are determined by medical history, physical examination (if required), and clinical judgment of the investigator to be eligible for inclusion in the study.
- Capable of giving signed informed consent as described in the protocol, which includes compliance with the requirements and restrictions listed in the ICD and in this protocol.
Exclusion Criteria:
- Medical or psychiatric condition, including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality, that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study.
- History of severe adverse reaction associated with any vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s).
- Immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination.
- Bleeding diathesis or condition associated with prolonged bleeding that would, in the opinion of the investigator, contraindicate intramuscular injection.
- Allergy to egg proteins (egg or egg products) or chicken proteins.
- Individuals who receive treatment with radiotherapy or immunosuppressive therapy, including cytotoxic agents or systemic corticosteroids (if systemic corticosteroids are administered for ≥14 days at a dose of ≥20 mg/day of prednisone or equivalent), eg, for cancer or an autoimmune disease, or planned receipt throughout the study. Inhaled/nebulized, intra-articular, intrabursal, or topical (skin or eyes) corticosteroids are permitted.
- Receipt of blood/plasma products, immunoglobulin, or monoclonal antibodies, from 60 days before study intervention administration, or planned receipt throughout the study.
- Vaccination with any investigational or licensed influenza vaccine within 6 months (175 days) before study intervention administration, or ongoing receipt of chronic antiviral therapy with activity against influenza.
- Any participant who has received or plans to receive a modRNA-platform SARS CoV-2 vaccine within 14 days before or after study vaccination at Visit 1.
- Participation in other studies involving administration of a study intervention within 28 days prior to, and/or during, participation in this study.
- Investigator site staff directly involved in the conduct of the study and their family members, site staff otherwise supervised by the investigator, and sponsor and sponsor delegate employees directly involved in the conduct of the study and their family members.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05540522
Contact: Pfizer CT.gov Call Center | 1-800-718-1021 | ClinicalTrials.gov_Inquiries@pfizer.com |

Study Director: | Pfizer CT.gov Call Center | Pfizer |
Responsible Party: | Pfizer |
ClinicalTrials.gov Identifier: | NCT05540522 |
Other Study ID Numbers: |
C4781004 |
First Posted: | September 14, 2022 Key Record Dates |
Last Update Posted: | May 30, 2023 |
Last Verified: | May 2023 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | Yes |
Plan Description: | 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. |
URL: | https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Grippe Flu Influenza Vaccine RNA vaccine |
Influenza, Human Respiratory Tract Infections Infections Orthomyxoviridae Infections RNA Virus Infections |
Virus Diseases Respiratory Tract Diseases Vaccines Immunologic Factors Physiological Effects of Drugs |