Study to Evaluate Immunogenicity and Safety of a High-Dose Influenza Vaccine in Adults 50 Through 64 Years of Age

NCT ID: NCT06641180

Last Updated: 2025-12-03

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

PHASE3

Total Enrollment

1180 participants

Study Classification

INTERVENTIONAL

Study Start Date

2024-11-04

Study Completion Date

2025-06-24

Brief Summary

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The purpose of this study is to evaluate Immunogenicity and Safety of a High-Dose (HD) Influenza Vaccine (IV) in Adults 50 through 64 Years of Age.

Detailed Description

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The study duration will be approximately 180 days (+ 14 days).

Conditions

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Influenza

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

PREVENTION

Blinding Strategy

QUADRUPLE

Participants Caregivers Investigators Outcome Assessors
Modified double-blind:

* Participants, Sponsor study staff\*, investigators, and study site staff will not know which study vaccine is administered during the study conduct
* Dedicated study site staff who prepare/administer the study interventions and are not involved in the safety evaluation will know which study vaccine is administered.

* Select sponsor staff will be unblinded after the code break for primary completion analysis.

Study Groups

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IIV-HD

Participants will receive a single intramuscular (IM) injection of IIV-HD at Day 1

Group Type EXPERIMENTAL

High-Dose trivalent influenza vaccine (Split virion, Inactivated)

Intervention Type BIOLOGICAL

Liquid suspension for intramuscular injection

IIV-SD

Participants will receive a single intramuscular (IM) injection of IIV-SD at Day 1

Group Type ACTIVE_COMPARATOR

Standard-dose trivalent influenza vaccine (Split virion, Inactivated)

Intervention Type BIOLOGICAL

Liquid suspension for intramuscular injection

Interventions

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High-Dose trivalent influenza vaccine (Split virion, Inactivated)

Liquid suspension for intramuscular injection

Intervention Type BIOLOGICAL

Standard-dose trivalent influenza vaccine (Split virion, Inactivated)

Liquid suspension for intramuscular injection

Intervention Type BIOLOGICAL

Eligibility Criteria

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Inclusion Criteria

* Aged 50 to 64 years on the day of inclusion.
* A female participant is eligible to participate if she is not pregnant or breastfeeding and one of the following conditions applies:

* Is of non-childbearing potential. To be considered of non-childbearing potential, a female must be postmenopausal for at least 1 year, or surgically sterile.

OR

* Is of childbearing potential and agrees to use an effective contraceptive method or abstinence from at least 4 weeks prior to study intervention administration until at least 4 weeks after study intervention administration.
* A female participant of childbearing potential must have a negative highly sensitive pregnancy test (urine or serum as required by local regulation) at enrollment before the first dose of study intervention.

* Informed consent form has been signed and dated.
* Able to attend all scheduled visits and to comply with all study procedures.

Exclusion Criteria

* Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within the preceding 6 months; or long-term systemic corticosteroid therapy (prednisone or equivalent for more than 2 consecutive weeks within the past 3 months).
* Personal or family history of Guillain-Barré Syndrome (GBS).
* Known systemic hypersensitivity to any of the study intervention components (Section 1.1, Section 6.1), or history of a life-threatening reaction to the study intervention used in the study or to a product containing any of the same substances.
* Self-reported thrombocytopenia, contraindicating intramuscular injection, based on investigator's judgment.
* Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating intramuscular injection, based on investigator's judgment.
* Chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with study conduct or completion.
* Moderate or severe acute illness/infection (according to investigator judgment) or febrile illness (temperature ≥ 38.0°C \[≥ 100.4°F\]) on the day of study intervention administration. A prospective participant should not be included in the study until the condition has resolved or the febrile event has subsided.
* Alcohol, prescription drug, or substance abuse that, in the opinion of the Investigator, might interfere with the study conduct or completion.
* Receipt of any vaccine in the 4 weeks preceding the study intervention administration or planned receipt of any vaccine prior to the second blood drawing (ie. approximately 4 weeks after the study intervention administration).
* Previous vaccination against influenza in the previous 6 months with an investigational or marketed vaccine.
* Receipt of immune globulins, blood, or blood-derived products in the past 3 months.
* Participation at the time of study enrollment (or in the 4 weeks preceding the first study intervention administration) or planned participation during the present study period in another clinical study investigating a vaccine, drug, medical device, or medical procedure.
* Deprived of freedom by an administrative or court order, or being in an emergency setting, or hospitalized involuntarily.
* Identified as an Investigator or employee of the Investigator or study center with direct involvement in the proposed study, or identified as an immediate family member (ie.

parent, spouse, natural or adopted child) of the Investigator or employee with direct involvement in the proposed study.
Minimum Eligible Age

50 Years

Maximum Eligible Age

64 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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Sanofi Pasteur, a Sanofi Company

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Locations

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CenExel CNS- Site Number : 8400005

Los Alamitos, California, United States

Site Status

Alliance for Multispeciality Research - Fort Myers- Site Number : 8400019

Fort Myers, Florida, United States

Site Status

Research Centers of America - Hollywood- Site Number : 8400010

Hollywood, Florida, United States

Site Status

IACT Health - Columbus - Talbotton Road- Site Number : 8400011

Columbus, Georgia, United States

Site Status

Cenexel IRA - iResearch Atlanta- Site Number : 8400007

Decatur, Georgia, United States

Site Status

The Hope Clinic of Emory Vaccine Center- Site Number : 8400017

Decatur, Georgia, United States

Site Status

Centricity Research - Rincon- Site Number : 8400012

Rincon, Georgia, United States

Site Status

Cenexel IRS - iResearch Savannah- Site Number : 8400008

Savannah, Georgia, United States

Site Status

Alliance for Multispeciality Research - Newton- Site Number : 8400003

Newton, Kansas, United States

Site Status

Alliance for Multispeciality Research - Lexington- Site Number : 8400002

Lexington, Kentucky, United States

Site Status

CBH Health - Gaithersburg- Site Number : 8400004

Gaithersburg, Maryland, United States

Site Status

Hassman Research Institute - Berlin- Site Number : 8400006

Berlin, New Jersey, United States

Site Status

Centricity Morehead- Site Number : 8400014

Morehead City, North Carolina, United States

Site Status

Centricity New Bern- Site Number : 8400015

New Bern, North Carolina, United States

Site Status

Aventiv Research Columbus- Site Number : 8400016

Columbus, Ohio, United States

Site Status

Kaiser Permanente Center for Health Research- Site Number : 8400018

Portland, Oregon, United States

Site Status

Alliance for Multispecialty Research - Volunteer Research Group- Site Number : 8400001

Knoxville, Tennessee, United States

Site Status

JBR Clinical Research- Site Number : 8400009

Salt Lake City, Utah, United States

Site Status

Centricity Research - Suffolk Primary Care - Centricity - PPDS- Site Number : 8400013

Suffolk, Virginia, United States

Site Status

Kaiser Permanente Washington- Site Number : 8400024

Seattle, Washington, United States

Site Status

Countries

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United States

Related Links

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Other Identifiers

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U1111-1305-7370

Identifier Type: REGISTRY

Identifier Source: secondary_id

QHD00042

Identifier Type: -

Identifier Source: org_study_id

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