Immune Response to High-Dose vs. Standard Dose Influenza Vaccine

September 30, 2026 updated by: Health Sciences North Research Institute

This 5-year proposal is a randomized study of split-virus influenza vaccine (SVV) in a high-dose (HD) vs. standard-dose (SD) formulation in each of five influenza seasons to define the key determinants of vaccine-mediated protection against influenza and how these immunologic mediators may be enhanced by vaccination with a newly approved high-dose influenza vaccine in older people

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

393

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Ontario
      • Greater Sudbury, Ontario, Canada, P3E 5J1
        • Health Sciences North Research Institute
  • United States
    • Connecticut
      • Farmington, Connecticut, United States, 06030
        • Center on Aging, UConn Health

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

20 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  1. Written informed consent provided by the participant

  2. Age 20-40 years old with no underlying chronic diseases or age ≥65 years old

  3. Willing to receive influenza vaccination

  4. Older cohort has received their influenza vaccine for the previous influenza season

    -

Exclusion Criteria:

  1. Immunosuppressive disorders or medications (including oral prednisone in doses >10 mg daily)

  2. Have not received influenza vaccination in the past or cannot be vaccinated due to previous severe reaction to influenza vaccine, egg, latex, or thimerosol allergies, or refusal of vaccination

  3. Participant has received a community available influenza vaccine for the approaching influenza season

  4. Females who are pregnant at Visit 1 (a pregnancy test will be administered for all females of child-bearing potential)

    -

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Factorial Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Flu Vaccine SD

Fluzone Standard Dose Influenza Vaccine
Biological: Flu Vaccine
Other Names:
  • Fluzone HD
Active Comparator: Flu Vaccine HD

Fluzone High Dose Influenza Vaccine
Biological: Flu Vaccine
Other Names:
  • Fluzone HD

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Number of Influenza Cases
Time Frame: five years

Influenza surveillance includes weekly contact with study subjects to assess for any flu-like symptoms or acute respiratory infection (ARI), and include nasopharyngeal swabs (within 5 days of onset of symptoms) for polymerase chain reaction (PCR) detection of influenza virus and post-influenza season detection of an antibody response to influenza infection. Routine screen for symptoms of ARI will also occur at the 4, 10 and 20 week visits when blood samples are collected. Influenza illness will be documented by PCR detection of influenza during an IARI or seroconversion (4-fold rise in antibody titers) in association with an ARI. ARI includes upper (coryza or sore throat) or lower (cough or shortness of breath) respiratory tract symptoms, or headache, malaise, myalgia or fever (> 99°F or 37.3°C orally or 100°F rectally) [41]. as physician visits, hospitalizations and deaths attributed to acute cardiopulmonary illness and will be tracked through the influenza season.
five years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Health Sciences North Research Institute

Collaborators

UConn Health

Investigators

  • Principal Investigator: Janet E McElhaney, MD, Health Sciences North Research Institute

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 1, 2014

Primary Completion (Actual)

September 21, 2026

Study Completion (Actual)

September 21, 2026

Study Registration Dates

First Submitted

November 3, 2014

First Submitted That Met QC Criteria

November 19, 2014

First Posted (Estimated)

November 21, 2014

Study Record Updates

Last Update Posted (Actual)

October 5, 2026

Last Update Submitted That Met QC Criteria

September 30, 2026

Last Verified

February 1, 2021

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • NIH R01

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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