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Completed Phase 2 Interventional Accepts healthy volunteers Results available

Safety and Immunogenicity of Different Formulations of an MF59-Adjuvanted Influenza Vaccine in Older Adults ≥50 Years of Age

ClinicalTrials.gov ID: NCT05501561

Public ClinicalTrials.gov record NCT05501561. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.

ClinicalTrials.gov public records Last synced Sep 11, 2026, 12:07 AM EDT

Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.

Official title

A Phase 2b, Randomized, Observer-Blind, Antigen and Adjuvant Dose-Confirmation Clinical Study to Evaluate Safety and Immunogenicity of Different Formulations of MF59-Adjuvanted Quadrivalent Subunit Inactivated Cell-derived Influenza Vaccine (aQIVc) in Older Adults ≥50 Years of Age

Brief summary

Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.

This Phase 2, randomized, observer-blind, dose-confirmation clinical study evaluated different formulations of MF59-Adjuvanted Quadrivalent Subunit Inactivated Influenza Vaccine. Approximately 1000 subjects were randomized into 1 of 4 possible treatment groups with approximately 250 participants per group. Every participant received an influenza vaccine injection on Day 1 and were to be followed up for approximately 6 months following injection. The primary immunogenicity analysis is based on Day 29 serology data.

Study identification

NCT ID
NCT05501561
Recruitment status
Completed
Study type
Interventional
Phase
Phase 2
Lead sponsor
Seqirus
Industry
Enrollment
1,056 participants

Conditions and interventions

Eligibility (public fields only)

Age range
50 Years and older
Sex
All
Healthy volunteers
Accepts healthy volunteers

This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.

Study timeline

Start date
Aug 24, 2022
Primary completion
Mar 30, 2023
Completion
Mar 30, 2023
Last update posted
Jun 29, 2026

2022 – 2023

United States locations

U.S. sites
47
U.S. states
25
U.S. cities
45
Facility City State ZIP Site status
AMR Tempe Tempe Arizona 85281
Marvel Clinical Research Huntington Beach California 92647
California Research Center San Diego California 92123
The Lynn Institute of The Rockies Colorado Springs Colorado 80920
Clinical Research Consulting, LLC Milford Connecticut 06460
Innovative Research of West Florida, Inc. Clearwater Florida 33756
Velocity Clinical Research - New Smyrna Beach Edgewater Florida 32132
CenExel RCA Hollywood Florida 33024
Health Awareness INC Jupiter Florida 33458
Global Health Research Center Miami Lakes Florida 33016
Precision Clinical Research Sunrise Florida 33351
Global Health Research Center Tampa Florida 33615
Platinum Research Network, LLC Savannah Georgia 31405
Meridian Clinical Research - Savannah Savannah Georgia 31406
AMR El Dorado El Dorado Kansas 67042
AMR Lexington Lexington Kentucky 40509
Meridian Clinical Research Baton Rouge Louisiana 70808
Medpharmics, LLC Metairie Louisiana 70006
Rockville Internal Medicine Group Rockville Maryland 20854
MedPharmics LLC Biloxi Mississippi 39531
Healthcare Research Network Hazelwood Missouri 63042
The Center for Pharmaceutical Research Kansas City Missouri 64114
Sundance Clinical Research, LLC St Louis Missouri 63141
Meridian Clinical Research Bellevue Nebraska 68005
Meridian Clinical Research Grand Island Nebraska 68803
Meridian Clinical Research, LLC Lincoln Nebraska 68510
Alliance for Multispecialty Research, LLC, Las Vegas Las Vegas Nevada 89119
Meridian Clinical Research (Binghamton, NY) Binghamton New York 13901
Meridian Clinical Research, LLC Endwell New York 13760
Velocity Clinical Research - Syracuse Syracuse New York 13057
M3 Wake Research, Inc. Raleigh North Carolina 27612
Meridian Clinical Research, LLC Cincinnati Ohio 45219
Meridian Clinical Research, LLC Cincinnati Ohio 45246
Aventiv Research, Inc. Columbus Columbus Ohio 43213
Lynn Health Science Institute Oklahoma City Oklahoma 73112
Velocity Clinical Research - Medford Medford Oregon 97504
Velocity Clinical Research, Gaffney Gaffney South Carolina 29340
Velocity Clinical Research - Greenville Greenville South Carolina 29615
Velocity Clinical Research, Spartanburg Spartanburg South Carolina 29303
Meridian Clinical Research - Dakota Dunes Dakota Dunes South Dakota 57049
AMR Coastal Clinical Research Knoxville Tennessee 37920
DM Clinical Research Tomball Texas 77375
JBR Clinical Research Salt Lake City Utah 84107
Velocity Clinical Research - West Jordan West Jordan Utah 84088
CVS pharmacy - Charlottesville Charlottesville Virginia 22902
CVS pharmacy - Reston Reston Virginia 20190
CVS pharmacy - Richmond Richmond Virginia 23235

Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.

About this trial record page

What this page shows
Public field values for ClinicalTrials.gov record NCT05501561, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
What this page does not do
No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
Where the data comes from
Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
Last refresh
Last update posted Jun 29, 2026 · Synced Sep 11, 2026

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Open the official record

The complete protocol, eligibility criteria, and contact information for NCT05501561 live on ClinicalTrials.gov.

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