NCT06518577

Immunogenicity of Influenza Vaccinations

Measuring Immunity Against Circulating Influenza Viruses: Randomized Immunogenicity Study Among US Adults Aged 18-64 Years Comparing Two Approved Influenza Vaccines

• Status: Completed
• Phase: Phase 4
• Study type: Interventional
• Enrollment: 605 (actual)
• Sponsor: Duke University · Academic / Other
• Sex: All
• Age: 18 Years – 64 Years
• Healthy volunteers: Accepted

Summary

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 or Fluzone). 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 \[28 days after acute visit if lab-confirmed positive for influenza\]).

Conditions

• Influenza

Interventions

Type	Name	Description
BIOLOGICAL	Flucelvax (ccIIV4)	Participants will receive Flucelvax (ccIIV4)
BIOLOGICAL	Flublok (RIV) or Fluzone (IIV)	Participants will receive Flublok (RIV) or Fluzone (IIV)

Timeline

• Start date: 2024-09-09
• Primary completion: 2024-12-09
• Completion: 2025-06-04
• First posted: 2024-07-24
• Last updated: 2025-06-19

Locations

7 sites across 1 country: United States

Regulatory

• FDA-regulated drug study