Immunogenicity and Safety Study of an Inactivated Influenza Vaccine (Split Virus, Vero Cell Derived) in Adults Aged 50 Years and Older
Public ClinicalTrials.gov record NCT00782431. 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.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
Phase 3 Double Blind Clinical Study of Effectiveness and Safety of Vero Cell-Derived, Trivalent, Seasonal Influenza Vaccine in Adults Aged 50 Years and Older
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
The purpose of this study is to demonstrate the effectiveness (seroprotection and seroconversion as measured by the hemagglutination inhibition \[HI\] assay) of an investigational Vero cell-derived, trivalent, seasonal influenza vaccine in adults 50 years of age and older. Subjects will be randomized in a double-blind fashion to receive a single intramuscular injection of either the investigational vaccine or a licensed egg-derived seasonal influenza vaccine. Blood will be drawn from all subjects for a determination of HI antibody titers on Days 0 and 21, body temperature and injection site reactions will be monitored daily for 7 days. In addition, subjects will be monitored for adverse events and rises in body temperature until Day 21 and again until Day 180.
Study identification
- NCT ID
- NCT00782431
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 3
- Enrollment
- 3,208 participants
Conditions and interventions
Conditions
Interventions
- Vero cell derived, trivalent, seasonal influenza vaccine Biological
- Licensed egg-derived, trivalent seasonal influenza vaccine Biological
Biological
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
- Oct 31, 2008
- Primary completion
- Nov 30, 2008
- Completion
- Jun 30, 2009
- Last update posted
- Jan 1, 2026
2008 – 2009
United States locations
- U.S. sites
- 30
- U.S. states
- 16
- U.S. cities
- 28
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| Coastal Clinical Research, Inc. | Mobile | Alabama | 36608 | — |
| Quality of Life Medical & Research Center, LLC | Tucson | Arizona | 85712 | — |
| Benchmark Research, San Francisco | Sacramento | California | 95816 | — |
| California Research Foundation | San Diego | California | 92103-6204 | — |
| Benchmark Research San Francisco | San Francisco | California | 94102 | — |
| Clinical Research of South Florida | Coral Gables | Florida | 33134 | — |
| Jacksonville Center for Clinical Research | Jacksonville | Florida | 32216 | — |
| University Clinical Research, Inc. | Pembroke Pines | Florida | 33024 | — |
| Clinical Research Atlanta | Stockbridge | Georgia | 30281 | — |
| Johnson County Clin-Trials | Lenexa | Kansas | 66219 | — |
| Vince and Associates Clinical Research | Overland Park | Kansas | 66212 | — |
| Heartland Research Associates, LLC | Wichita | Kansas | 67205 | — |
| Heartland Research Associates LLC | Wichita | Kansas | 67207 | — |
| Central Kentucky Research Associates, Inc. | Lexington | Kentucky | 40509 | — |
| Center for Pharmaceutical Research | Kansas City | Missouri | 64114 | — |
| Radiant Research, Inc. | St Louis | Missouri | 63141 | — |
| Sundance Clinical Research | St Louis | Missouri | 63141 | — |
| Meridian Clinical Research, LLC | Omaha | Nebraska | 68134 | — |
| Regional Clinical Research, Inc. | Endwell | New York | 13760 | — |
| Rochester Clinical Research Inc. | Rochester | New York | 14609 | — |
| Wake Research Associates, LLC | Raleigh | North Carolina | 27612 | — |
| Omega Medical Research | Warwick | Rhode Island | 02886 | — |
| Palmetto Medical Research | Mt. Pleasant | South Carolina | 29464 | — |
| Clinical Research Associates, Inc. - Nashville | Nashville | Tennessee | 37203 | — |
| Benchmark Research Austin | Austin | Texas | 78705 | — |
| Benchmark Research Ft. Worth | Fort Worth | Texas | 76135 | — |
| Research Across America | Plano | Texas | 75093 | — |
| Benchmark Research San Angelo | San Angelo | Texas | 76904 | — |
| Pi-Coor Clinical Research | Fairfax | Virginia | 22030 | — |
| Clinical Research Associates of Tidewater | Norfolk | Virginia | 23507 | — |
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 NCT00782431, 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 Jan 1, 2026 · Synced Sep 26, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT00782431 live on ClinicalTrials.gov.