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

A Phase 3, Randomized, Modified Double-blind, 2-arm Study to Evaluate the Immunogenicity and Safety of High-Dose Inactivated Influenza Vaccine (IIV-HD) Compared With a Standard-dose Inactivated Influenza Vaccine (IIV-SD) in Participants 50 Through 64 Years of Age.

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.

Study Overview

• Status: Completed
• Conditions: Influenza
• Intervention / Treatment: Biological: High-Dose trivalent influenza vaccine (Split virion, Inactivated); Biological: Standard-dose trivalent influenza vaccine (Split virion, Inactivated)

Detailed Description

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

• Study Type: Interventional
• Enrollment (Actual): 1180
• Phase: Phase 3

Contacts and Locations

Study Locations

• United States
  • California
    • Los Alamitos, California, United States, 90720
      • CenExel CNS- Site Number : 8400005
  • Florida
    • Fort Myers, Florida, United States, 33912
      • Alliance for Multispeciality Research - Fort Myers- Site Number : 8400019
    • Hollywood, Florida, United States, 33024
      • Research Centers of America - Hollywood- Site Number : 8400010
  • Georgia
    • Columbus, Georgia, United States, 31904
      • IACT Health - Columbus - Talbotton Road- Site Number : 8400011
    • Decatur, Georgia, United States, 30030
      • Cenexel IRA - iResearch Atlanta- Site Number : 8400007
    • Decatur, Georgia, United States, 30030
      • The Hope Clinic of Emory Vaccine Center- Site Number : 8400017
    • Rincon, Georgia, United States, 31406
      • Centricity Research - Rincon- Site Number : 8400012
    • Savannah, Georgia, United States, 31405
      • Cenexel IRS - iResearch Savannah- Site Number : 8400008
  • Kansas
    • Newton, Kansas, United States, 67114
      • Alliance for Multispeciality Research - Newton- Site Number : 8400003
  • Kentucky
    • Lexington, Kentucky, United States, 40509
      • Alliance for Multispeciality Research - Lexington- Site Number : 8400002
  • Maryland
    • Gaithersburg, Maryland, United States, 20877
      • CBH Health - Gaithersburg- Site Number : 8400004
  • New Jersey
    • Berlin, New Jersey, United States, 08009
      • Hassman Research Institute - Berlin- Site Number : 8400006
  • North Carolina
    • Morehead City, North Carolina, United States, 28557
      • Centricity Morehead- Site Number : 8400014
    • New Bern, North Carolina, United States, 28562
      • Centricity New Bern- Site Number : 8400015
  • Ohio
    • Columbus, Ohio, United States, 43213
      • Aventiv Research Columbus- Site Number : 8400016
  • Oregon
    • Portland, Oregon, United States, 97227
      • Kaiser Permanente Center for Health Research- Site Number : 8400018
  • Tennessee
    • Knoxville, Tennessee, United States, 37920
      • Alliance for Multispecialty Research - Volunteer Research Group- Site Number : 8400001
  • Utah
    • Salt Lake City, Utah, United States, 84107
      • JBR Clinical Research- Site Number : 8400009
  • Virginia
    • Suffolk, Virginia, United States, 23435-3763
      • Centricity Research - Suffolk Primary Care - Centricity - PPDS- Site Number : 8400013
  • Washington
    • Seattle, Washington, United States, 98101
      • Kaiser Permanente Washington- Site Number : 8400024

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: IIV-HD; Participants will receive a single intramuscular (IM) injection of IIV-HD at Day 1	Biological: High-Dose trivalent influenza vaccine (Split virion, Inactivated); Liquid suspension for intramuscular injection
Active Comparator: IIV-SD; Participants will receive a single intramuscular (IM) injection of IIV-SD at Day 1	Biological: Standard-dose trivalent influenza vaccine (Split virion, Inactivated); Liquid suspension for intramuscular injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Geometric mean titers (GMTs) against influenza vaccine antibodies (Ab)	GMTs of anti-influenza antibodies were measured using hemagglutination inhibition (HAI) assay for 3 influenza virus strains: A/H1N1, A/H3N2, and B/Victoria lineage.	Day 1 and Day 29
Percentage of participants with seroconversion for influenza vaccine antibodies	Anti-influenza antibodies will be measured using HAI assay for 3 influenza virus strains: A/H1N1, A/H3N2, and B/Victoria lineage. Seroconversion status 28 days after vaccination (ie, preinjection Ab titer < 10 [1/dil] at Day 1 and post-injection Ab titer≥ 40 [1/dil] at Day 29 or preinjection Ab titer ≥ 10 [1/dil] at Day 1 and a ≥ 4-fold increase in titer [1/dil] at Day 29).	Day 29

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Geometric Mean of Individual Titer Ratio (GMTR)	GMTRs will be measured using HAI assay for 3 influenza virus strains: A/H1N1, A/H3N2, and B/Victoria lineage. Individual HAI antibody titer ratio Day 29/Day 1.	Day 1 and Day 29
Percentage of participants with detectable HAI titer (HAI titer ≥ 10 [1/dil])	Anti-influenza antibodies will be measured using HAI assay for 3 influenza virus strains: A/H1N1, A/H3N2, and B/Victoria lineage. Percentage of participants with HAI antibody titer >=10 (1/dil)	Day 1 and Day 29
Percentage of participants with HAI titer ≥ 40 (1/dil)	Anti-influenza antibodies will be measured using HAI assay for 3 influenza virus strains: A/H1N1, A/H3N2, and B/Victoria lineage. Percentage of participants with HAI antibody titers ≥ 40 (1/dil)	Day 29
Number of participants with immediate adverse events (AEs)	Immediate events are recorded to capture medically relevant unsolicited systemic AEs which occur within the first 30 minutes after vaccination.	Within 30 minutes after vaccination
Number of participants with solicited injection site reactions	Solicited injection site reactions (pre-listed in the participant diary and CRF)	Up to 7 days after vaccination
Number of participants with solicited systemic reaction	Solicited systemic reactions (pre-listed in the participant diary and CRF)	Up to 7 days after vaccination
Number of participants with unsolicited AEs	An unsolicited AE is an observed AE that does not fulfill the conditions of solicited reactions, ie, pre-listed in the CRF in terms of diagnosis and onset window post-vaccination.	Up to 28 days after vaccination
Number of participants with medically attended adverse events (MAAEs)	An MAAE is a new-onset or a worsening of a condition that prompts the participant or participant's parent(s)/legally acceptable representative(s) to seek unplanned medical advice at a physician's office or Emergency Department.	Throughout the study, approximately 180 days
Number of participants with adverse events of special interest (AESIs)	An adverse event of special interest (serious or non-serious) is one of scientific and medical concern specific to the Sponsor's study intervention or program, for which ongoing monitoring and rapid communication by the investigator to the Sponsor can be appropriate.	Throughout the study, approximately 180 days
Number of participants with serious adverse events (SAEs)	A SAE is defined as any adverse event that, at any dose 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, or was other medically important event.	Throughout the study, approximately 180 days

Collaborators and Investigators

• Sponsor: Sanofi Pasteur, a Sanofi Company

Publications and helpful links

Helpful Links

• QHD00042 Plain Language Results Summary

Study record dates

Study Major Dates

• Study Start (Actual): November 4, 2024
• Primary Completion (Actual): January 28, 2025
• Study Completion (Actual): June 24, 2025

Study Registration Dates

• First Submitted: October 11, 2024
• First Submitted That Met QC Criteria: October 11, 2024
• First Posted (Actual): October 15, 2024

Study Record Updates

• Last Update Posted (Estimated): December 3, 2025
• Last Update Submitted That Met QC Criteria: December 2, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Respiratory Tract Infections; Infections; Orthomyxoviridae Infections; RNA Virus Infections; Virus Diseases; Respiratory Tract Diseases; Influenza, Human; Biological Products; Complex Mixtures; Vaccines; Viral Vaccines; Influenza Vaccines
• Other Study ID Numbers: QHD00042; U1111-1305-7370 (Registry Identifier: ICTRP)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Qualified researchers may request access to patient level data and related study documents including the clinical study report, study protocol with any amendments, blank case report form, statistical analysis plan, and dataset specifications. Patient level data will be anonymized and study documents will be redacted to protect the privacy of trial participants. Further details on Sanofi's data sharing criteria, eligible studies, and process for requesting access can be found at: https://vivli.org

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No