ClinicalTrials.gov record
Clostridium Difficile Vaccine 2-Dose Versus 3-Dose Study
ClinicalTrials.gov ID: NCT03918629
Public ClinicalTrials.gov record NCT03918629. 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 May 20, 2026, 12:31 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 3, RANDOMIZED OBSERVER-BLINDED STUDY TO EVALUATE THE IMMUNOGENICITY, SAFETY, AND TOLERABILITY OF 2 DOSES COMPARED TO 3 DOSES OF CLOSTRIDIUM DIFFICILE VACCINE IN ADULTS 50 YEARS OF AGE AND OLDER
Study identification
- NCT ID
- NCT03918629
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 3
- Lead sponsor
- Pfizer
- Industry
- Enrollment
- 1,994 participants
Conditions and interventions
Conditions
Interventions
- Clostridium difficile Biological
- Placebo 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
- Mar 31, 2019
- Primary completion
- Dec 21, 2020
- Completion
- Dec 21, 2020
- Last update posted
- Jan 9, 2024
2019 – 2020
United States locations
- U.S. sites
- 52
- U.S. states
- 22
- U.S. cities
- 46
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| North Alabama Research Center, LLC | Athens | Alabama | 35611 | — |
| Medical Affiliated Research Center | Huntsville | Alabama | 35801 | — |
| East Valley Gastroenterology and Hepatology Associates | Chandler | Arizona | 85224 | — |
| The Pain Center of Arizona | Peoria | Arizona | 85381 | — |
| HOPE Research Institute | Phoenix | Arizona | 85018 | — |
| The Pain Center of Arizona | Phoenix | Arizona | 85018 | — |
| The Pain Center of Arizona | Phoenix | Arizona | 85032 | — |
| Paradigm Clinical Research Centers, Inc. | La Mesa | California | 91942 | — |
| Paradigm Clinical Research Centers, Inc. | Redding | California | 96001 | — |
| Paradigm Research | Wheat Ridge | Colorado | 80033 | — |
| Innovative Research of West Florida, Inc. | Clearwater | Florida | 33756 | — |
| Accel Research Sites - DeLand Clinical Research Unit | DeLand | Florida | 32720 | — |
| Acevedo Clinical Research Associates | Miami | Florida | 33142 | — |
| Clinical Neuroscience Solutions, Inc. | Orlando | Florida | 32801 | — |
| Clinical Neuroscience Solutions, Inc. | Orlando | Florida | 32806 | — |
| Pines Care Research Center, LLC | Pembroke Pines | Florida | 33026 | — |
| Progressive Medical Research | Port Orange | Florida | 32127 | — |
| Meridian Clinical Research, LLC | Savannah | Georgia | 31406 | — |
| Snake River Research, PLLC | Idaho Falls | Idaho | 83404 | — |
| MOC Research | Mishawaka | Indiana | 46544 | — |
| MedPharmics, LLC | Metairie | Louisiana | 70006 | — |
| MedPharmics, LLC | Gulfport | Mississippi | 39503 | — |
| Clinical Research Professionals Inc. | Chesterfield | Missouri | 63005 | — |
| Amici Clinical Research | Raritan | New Jersey | 08869 | — |
| Rochester Clinical Research, Inc | Rochester | New York | 14609 | — |
| PMG Research of Charlotte LLC | Charlotte | North Carolina | 28209 | — |
| PharmQuest | Greensboro | North Carolina | 27408 | — |
| Accellacare - Hickory | Hickory | North Carolina | 28601 | — |
| PMG Research of Raleigh | Raleigh | North Carolina | 27609 | — |
| PMG Research of Wilmington, LLC | Wilmington | North Carolina | 28401 | — |
| PMG Research of Winston-Salem, LLC | Winston-Salem | North Carolina | 27103 | — |
| Lillestol Research LLC | Fargo | North Dakota | 58104 | — |
| Aventiv Research Inc. | Columbus | Ohio | 43213 | — |
| PriMed Clinical Research | Dayton | Ohio | 45419 | — |
| Medical Research South | Goose Creek | South Carolina | 29445 | — |
| Main Street Physician's Care - Waterway | Little River | South Carolina | 29566 | — |
| Coastal Carolina Research Center | North Charleston | South Carolina | 29405 | — |
| Holston Medical Group | Bristol | Tennessee | 37620 | — |
| ARC Clinical Research at Wilson Parke | Austin | Texas | 78726 | — |
| Bellaire Doctor's Clinic | Bellaire | Texas | 77401 | — |
| Texas Health Care, PLLC | Fort Worth | Texas | 76104 | — |
| Ventavia Research Group, LLC | Fort Worth | Texas | 76104 | — |
| Texas Center for Drug Development, Inc. | Houston | Texas | 77081 | — |
| Diagnostics Research Group | San Antonio | Texas | 78229 | — |
| DM Clinical Research | Tomball | Texas | 77375 | — |
| Martin Diagnostic Clinic | Tomball | Texas | 77375 | — |
| J. Lewis Research Inc. / Foothill Family Clinic Draper | Draper | Utah | 84020 | — |
| J. Lewis Research, Inc. / Foothill Family Clinic | Salt Lake City | Utah | 84109 | — |
| J. Lewis Research, Inc. / Foothill Family Clinic South | Salt Lake City | Utah | 84121 | — |
| J. Lewis Research, Inc. / Jordan River Family Medicine | South Jordan | Utah | 84095 | — |
| Virginia Research Center LLC | Midlothian | Virginia | 23114 | — |
| Wenatchee Valley Hospital & Clinics | Wenatchee | Washington | 98801 | — |
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 NCT03918629, 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 9, 2024 · Synced May 20, 2026
Related: full search, browse by condition, browse by drug or therapy, browse by sponsor, browse by U.S. city.
Open the official record
The complete protocol, eligibility criteria, and contact information for NCT03918629 live on ClinicalTrials.gov.