Immunogenicity of Influenza Vaccinations

Duke University606 enrolled

Overview

This study is a randomized immunogenicity study in an enrolled cohort with active surveillance for influenza-like illness (ILI). During this study, participants will be randomly assigned to receive an approved cell culture-based influenza vaccine (Flucelvax®) versus a licensed comparator influenza vaccine (Flublok®). Blood samples from participants will be collected for measurement of biomarkers of immune response at baseline (visit 1; day 1), post-vaccination (visit 2; day 29), and post-season (visit 3; day 181). Participants will be asked if they wish to also provide saliva specimens at baseline (visit 1; day 1), post-vaccination (visit 2; day 29), and post-season (visit 3; day 181). Serum and peripheral blood mononuclear cells (PBMC) and plasma samples will be isolated from whole blood and tested for biomarkers of vaccine immunogenicity, and duration of antibody responses. Participants will receive electronic surveys via email or text message weekly asking about changes in health status and new ILI symptoms; those reporting illness may be asked to provide a respiratory swab for laboratory testing for influenza and other respiratory viruses and up to 2 additional blood draws (acute \[\<10 days after symptom onset\] and convalescent \[28 days after acute visit if lab-confirmed positive for influenza\]).

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

NONE

Enrollment

606

Conditions

Influenza

Eligibility

Sex: ALLMin age: 18 YearsMax age: 64 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: 1. Adults aged 18-64 years that have not received the current season's influenza vaccine 2. English literate 3. Email or text message capability for weekly follow-up 4. Intention of receiving influenza vaccine based on ACIP-CDC guidelines 5. Willing to provide written/electronic informed consent 6. Intention of being available for entire study period and able to complete all relevant study procedures, including follow-up phone calls and clinic visits Exclusion Criteria: 1. Receipt of the current season's influenza vaccine (receipt after July 1, 2024) 2. History of severe allergic reaction after a previous dose of any influenza vaccine or to an influenza vaccine component 3. Receipt of any licensed or investigational live vaccine within 6 weeks or non-live vaccine within 2 weeks prior to enrollment in this study or planning receipt of any vaccines between visits 1 and 2 of the study (approximately within 4 weeks after the receipt of study-administered vaccine) 4. History of Guillain-Barré syndrome 5. Currently pregnant, planning to become pregnant within the first three months of the study per participant self-report 6. Bleeding diathesis or condition associated with prolonged bleeding that would, in the opinion of the investigator, contraindicate intramuscular injection. 7. Any condition which, in the opinion of the investigators, may pose a health risk to the participant or interfere with the evaluation of the study objectives Temporary Delay Criteria (Visit 1) 1\. History of febrile illness (\> 100.0°F or 37.8°C) within the past 72 hours prior to vaccine administration

Locations (7)

Valleywise Health Comprehensive Health Center

Phoenix, Arizona, United States

ASU Biodesign Institute

Tempe, Arizona, United States

Centers for Disease Control and Prevention

Atlanta, Georgia, United States

Washington University IDCRU

St Louis, Missouri, United States

University Hospitals Cleveland Medical Center

Cleveland, Ohio, United States

VA Northeast Ohio Healthcare System (VANEOHS)

Cleveland, Ohio, United States

Department of Family Medicine, University of Pittsburgh School of Medicine

Pittsburgh, Pennsylvania, United States

Outcomes

Primary Outcomes

Percent of Participants With a Seroprotective HAI Titer (≥1:40)

The percent of participants with a seroprotective antibody titer (≥1:40) for each influenza vaccine antigen was determined. Cell-grown A(H1N1)pdm09 and B/Victoria were measured by hemagglutination inhibition (HAI), while A(H3N2) titers were measured by microneutralization.

Time frame: Visit 2 (Days 28-42, Post-vaccination)

The Geometric Mean Titer (GMT) of HAI Antibody

The geometric mean antibody titer (GMT) for each influenza vaccine antigen in the 2024-2025 influenza season. GMTs were calculated as the anti-log of the mean of log-transformed titers. Cell-grown A(H1N1)pdm09 and B/Victoria were assessed by hemagglutination inhibition (HAI), whereas A(H3N2) was assessed by microneutralization.

Time frame: Up to Visit 2 (Days 28-42, Post-vaccination)

Percent of Participants Demonstrating Seroconversion From Baseline

The percent of participants in each vaccination group demonstrating seroconversion from Baseline at Day 29 (defined as a titer ≥1:40 at Day 29 if the baseline titer is \<1:10, or a ≥4-fold rise in titer at Day 29 if the baseline titer is ≥1:10) for each vaccine antigen. Viruses tested were cell-grown A(H1N1)pdm09 and B/Victoria using hemagglutination inhibition (HAI), and A(H3N2) using microneutralization.

Time frame: Day 29 post-vaccination assessment (Visit 2; scheduled for Day 29 with an allowable window of Days 28-42 post-vaccination)

Geometric Mean Fold Rise (GMFR) in HAI Titer From Baseline

The geometric mean fold rise (GMFR) in antibody titers from Baseline to Day 29 for each influenza vaccine antigen. Cell-grown A(H1N1)pdm09 and B/Victoria were assessed using hemagglutination inhibition (HAI), whereas A(H3N2) was assessed using microneutralization.