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Dynamics of the Immune Responses to Repeat Influenza Vaccination Exposures

NCT04576377 · Status: COMPLETED · Phase: PHASE4 · Type: INTERVENTIONAL · Enrollment: 977

Last updated 2026-05-15

No results posted yet for this study

Summary

The aims of this vaccine trial are: (1) to measure humoral and selected cellular immune responses to repeated influenza vaccination with Flublok, including these responses' associations with age, birth year, and prior vaccination history; (2) to identify the characteristics of study participants who are vaccinated but still become infected with influenza virus ("vaccine failures") and participants who have poor immune responses to vaccination; and (3) to predict how influenza vaccinations and infections shape immunity.

Conditions

  • Influenza, Human

Interventions

BIOLOGICAL

FluBlok

Recombinant HA quadrivalent influenza vaccine (0.5mL Flublok®, Sanofi Pasteur) containing 180μg antigen, 45μg for each influenza strain included.

OTHER

Placebo

0.5mL saline placebo.

Sponsors & Collaborators

  • University of Chicago

    collaborator OTHER

  • National Institute of Allergy and Infectious Diseases (NIAID)

    collaborator NIH

  • The University of Hong Kong

    lead OTHER

Study Design

Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
TRIPLE
Model
PARALLEL

Eligibility

Min Age
18 Years
Max Age
45 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2020-10-05
Primary Completion
2025-12-31
Completion
2025-12-31
FDA Drug
Yes

Countries

  • Hong Kong

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT04576377 on ClinicalTrials.gov