A Study to Learn About a Clostridioides Difficile Vaccine in People 65 Years of Age and Older

ClinicalTrials.gov ID: NCT07282665

Public ClinicalTrials.gov record NCT07282665. 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.

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ClinicalTrials.gov public records Last synced Sep 15, 2026, 4:22 PM 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, PLACEBO-CONTROLLED, DOUBLE-BLINDED, RANDOMIZED STUDY TO EVALUATE THE EFFICACY, SAFETY, AND TOLERABILITY OF A CLOSTRIDIOIDES DIFFICILE VACCINE IN ADULTS 65 YEARS OF AGE AND OLDER

Brief summary

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

The purpose of the study is to learn about how effective, safe, and tolerable the Clostridioides difficile (C. difficile) vaccine is in decreasing the number of C. difficile infections (pCDI) in adults 65 years of age or older. The participants will receive either the C. difficile vaccine or placebo (saline). A placebo does not contain any active ingredients. The vaccines will be given as a shot into the upper arm muscle. This study looks at the number of diarrhea (loose stools) events related to a C. difficile infection, so the length of the study can change. If these events happen quickly, the study may finish sooner; if they happen slowly, it could take longer. Sometimes, the study might stop early if the vaccine clearly does not work. Participants will stay in the study until enough events have occurred to answer the main question. On average, each person is expected to take part for up to about three and a half years. During this time, participants will have 3 planned clinic visits and 3 planned phone visits. After these visits, more scheduled clinic visits will happen every year until the end of study. Besides the scheduled study visits, if at any time during the study a participant has 3 or more loose stools in 24 hours, they will be asked to save the next one (the fourth or later) and contact the study site. The study site will check to see if it could be a C. difficile infection. This check may happen at the clinic or through a phone or video call.

Study identification

NCT ID: NCT07282665
Recruitment status: Recruiting
Study type: Interventional
Phase: Phase 3
Lead sponsor: Pfizer; Industry
Enrollment: 32,500 participants

Conditions and interventions

Conditions

Clostridoides Difficile Associated Disease

Interventions

C.difficile vaccine Biological
Saline Placebo Other

Biological · Other

Eligibility (public fields only)

Age range: 65 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: Dec 9, 2025
Primary completion: Dec 10, 2028
Completion: Jun 6, 2029
Last update posted: Sep 8, 2026

2025 – 2029

United States locations

U.S. sites: 141
U.S. states: 31
U.S. cities: 92

Facility	City	State	ZIP	Site status
North Alabama Research Center	Athens	Alabama	35611	Recruiting
Lakeview Clinical Research	Guntersville	Alabama	35976	Recruiting
Medical Affiliated Research Center	Huntsville	Alabama	35801	Recruiting
Chinle Center for Indigenous Health	Chinle	Arizona	86503	Recruiting
Chinle Comprehensive Health Care Facility	Chinle	Arizona	86503	Recruiting
Epic Medical Research-Sun City	Sun City	Arizona	85351	Recruiting
Applied Research Center of Arkansas	Little Rock	Arkansas	72205	Recruiting
Kaiser Permanente Daly City	Daly City	California	94015	Recruiting
Kaiser Permanente Los Angeles Medical Center	Los Angeles	California	90027	Recruiting
Kaiser Permanente Oncology Pharmacy #014C	Los Angeles	California	90027	Recruiting
Sacramento VA Medical Center	Mather	California	95655	Recruiting
Kaiser Permanente Oakland	Oakland	California	94611	Recruiting
Kaiser Permanente Ontario Medical Center	Ontario	California	91761	Recruiting
Kaiser Permanente Roseville	Roseville	California	95661	Recruiting
Kaiser Permanente Sacramento	Sacramento	California	95815	Recruiting
Kaiser Permanente South Sacramento	Sacramento	California	95823	Recruiting
Velocity Clinical Research, San Bernardino	San Bernardino	California	92408	Recruiting
Kaiser Permanente - San Diego Medical Center	San Diego	California	92123	Recruiting
Kaiser Permanente Viewridge Medical Office	San Diego	California	92123	Recruiting
Kaiser Permanente San Jose	San Jose	California	95119	Recruiting
Carbon Health - San Mateo - Hillsdale Mall	San Mateo	California	94403	Active, not recruiting
Kaiser Permanente Santa Clara	Santa Clara	California	95051	Recruiting
Med Partners, Inc. dba Premiere Medical Center of Burbank, Inc.	Toluca Lake	California	91602	Recruiting
Kaiser Permanente Walnut Creek	Walnut Creek	California	94596	Recruiting
Diablo Clinical Research, Inc.	Walnut Creek	California	94598	Recruiting
GW Vaccine Research Unit	Washington D.C.	District of Columbia	20037	Recruiting
The GW Medical Faculty Associates	Washington D.C.	District of Columbia	20037	Recruiting
Bay Pines VA Healthcare System	Bay Pines	Florida	33744	Recruiting
Proactive Clinical Research,LLC	Fort Lauderdale	Florida	33308	Recruiting
Clinical Neuroscience Solutions, LLC	Jacksonville	Florida	32256	Recruiting
M3 Wake Research - Lake City	Lake City	Florida	32055	Recruiting
South Florida Research Organization	Medley	Florida	33166	Recruiting
Care Research Inc	Miami	Florida	33130	Recruiting
Entrust Clinical Research	Miami	Florida	33176	Recruiting
Charisma Medical and Research Center	Miami Lakes	Florida	33014	Recruiting
Palm Springs Community Health Center	Miami Lakes	Florida	33014	Recruiting
Indago Research & Health Center, Inc	Miami Lakes	Florida	33016	Recruiting
Angels Clinical Research Institute	Tampa	Florida	33614	Recruiting
Emory Steiner Building Research Center	Atlanta	Georgia	30303	Recruiting
Emory University Woodruff Extension Building (WEB)	Atlanta	Georgia	30303	Recruiting
Centricity Research Columbus Georgia Multispecialty	Columbus	Georgia	31904	Recruiting
The Hope Clinic of Emory University	Decatur	Georgia	30030	Recruiting
Atlanta VA Medical Center	Decatur	Georgia	30033	Recruiting
Velocity Clinical Research, Savannah	Savannah	Georgia	31406	Recruiting
DM Clinical Research - Chicago	Melrose Park	Illinois	60160	Recruiting
Accellacare - McFarland	Ames	Iowa	50010	Recruiting
McFarland Clinic, PC	Ames	Iowa	50010	Recruiting
Velocity Clinical Research, Sioux City	Sioux City	Iowa	51106	Recruiting
AMR Clinical	Newton	Kansas	67114	Recruiting
Ochsner Medical Complex - The Grove	Baton Rouge	Louisiana	70836	Recruiting
Ochsner Lafayette General Medical Center	Lafayette	Louisiana	70503	Recruiting
Johns Hopkins Bloomberg School of Public Health	Baltimore	Maryland	21205	Recruiting
Johns Hopkins Bloomberg School of Public Health	Baltimore	Maryland	21231	Recruiting
VA Boston Healthcare System - West Roxbury	West Roxbury	Massachusetts	02132	Recruiting
Revive Research Institute, Inc.	Southfield	Michigan	48075	Recruiting
DM Clinical Research - Detroit	Southfield	Michigan	48076	Recruiting
Washington University School of Medicine	St Louis	Missouri	63110	Recruiting
Sundance Clinical Research	St Louis	Missouri	63141	Recruiting
Velocity Clinical Research, Grand Island	Grand Island	Nebraska	68803	Recruiting
University of Nebraska Medical Center	Omaha	Nebraska	68105	Recruiting
Velocity Clinical Research, Omaha	Omaha	Nebraska	68134	Recruiting
University Of Nebraska Medical Center	Omaha	Nebraska	68198	Recruiting
Renown Center for Advanced Medicine	Reno	Nevada	89502	Recruiting
Renown Regional Medical Center	Reno	Nevada	89502	Recruiting
University Health	Reno	Nevada	89519	Recruiting
Hackensack Meridian Health Hackensack University Medical Center	Hackensack	New Jersey	07601	Recruiting
HMH David Jurist Research Building	Hackensack	New Jersey	07601	Recruiting
HMH Hackensack University Medical Center	Hackensack	New Jersey	07601	Recruiting
Hackensack Meridian Health Jersey Shore University Medical Center	Neptune City	New Jersey	07753	Recruiting
HOPE Tower at Jersey Shore University Medical Center	Neptune City	New Jersey	07753	Recruiting
Rutgers Robert Wood Johnson Medical School	New Brunswick	New Jersey	08901	Recruiting
South Jersey Infectious Disease	Somers Point	New Jersey	08244	Recruiting
Albuquerque Clinical Trials, Inc.	Albuquerque	New Mexico	87102	Recruiting
Gallup Center for Indigenous Health	Gallup	New Mexico	87301	Recruiting
Gallup Indian Medical Center	Gallup	New Mexico	87301	Recruiting
Northern Navajo Medical Center	Shiprock	New Mexico	87420	Recruiting
Shiprock Center for Indigenous Health	Shiprock	New Mexico	87420	Recruiting
NYU Langone Health	Brooklyn	New York	11220	Recruiting
Upstate Global Health Institute	East Syracuse	New York	13057	Recruiting
Mount Sinai Queens	Long Island City	New York	11102	Recruiting
North Shore University Hospital	Manhasset	New York	11030	Recruiting
Northwell Health Infectious Disease	Manhasset	New York	11030	Recruiting
NYU Langone Health	Mineola	New York	11501	Recruiting
Northern Westchester Hospital	Mount Kisco	New York	10549	Recruiting
NYU Langone Health	New York	New York	10016	Recruiting
Mount Sinai West	New York	New York	10019	Recruiting
Mount Sinai Morningside	New York	New York	10025	Recruiting
Icahn School of Medicine at Mount Sinai	New York	New York	10029	Recruiting
Columbia University Irving Medical Center	New York	New York	10032	Recruiting
Rochester Clinical Research, LLC	Rochester	New York	14609	Recruiting
Phelps Hospital Geriatric Medicine & Improvement Science	Sleepy Hollow	New York	10591	Recruiting
Staten Island University Hospital	Staten Island	New York	10305	Recruiting
Montefiore Medical Center	The Bronx	New York	10467	Recruiting
James J. Peters VA Medical Center	The Bronx	New York	10468	Recruiting
Accellacare - Cary	Cary	North Carolina	27518	Recruiting
Duke Vaccine and Trials Unit	Durham	North Carolina	27703	Recruiting
Medication Management	Greensboro	North Carolina	27405	Recruiting
Accellacare - Hickory	Hickory	North Carolina	28601	Recruiting
Atrium Health Wake Forest Baptist Infectious Disease-High Point	High Point	North Carolina	27262	Recruiting
Accellacare - Raleigh	Raleigh	North Carolina	27609	Recruiting
Duke University Health System-Duke Vaccine and Trials Unit Raleigh	Raleigh	North Carolina	27609	Recruiting
Duke University Health System	Raleigh	North Carolina	27609	Recruiting
Raleigh Medical Group P.A.	Raleigh	North Carolina	27609	Recruiting
Accellacare - Salisbury	Salisbury	North Carolina	28144	Recruiting
Accellacare - Wilmington	Wilmington	North Carolina	28401	Recruiting
Wilmington Health, PLLC	Wilmington	North Carolina	28401	Recruiting
Accellacare - Winston-Salem	Winston-Salem	North Carolina	27103	Recruiting
Wake Forest Baptist Health	Winston-Salem	North Carolina	27157	Recruiting
CTI Clinical Research Center	Cincinnati	Ohio	45212	Recruiting
VA Northeast Ohio Healthcare System Louis Stokes Cleveland VA Medical Center	Cleveland	Ohio	44106	Recruiting
Kaiser Permanente Center for Health Research	Portland	Oregon	97227	Recruiting
Capital Area Research, LLC	Camp Hill	Pennsylvania	17011	Recruiting
DM Clinical Research - Philadelphia	Philadelphia	Pennsylvania	19107	Recruiting
Walker Family Care	Little River	South Carolina	29566	Recruiting
Velocity Clinical Research, Spartanburg	Spartanburg	South Carolina	29303	Recruiting
New Phase Research and Development	Knoxville	Tennessee	37909	Recruiting
Clinical Neuroscience Solutions, LLC	Memphis	Tennessee	38119	Recruiting
The Vanderbilt Vaccine Research Program Clinic at The Village at Vanderbilt	Nashville	Tennessee	37212	Recruiting
Vanderbilt Investigational Drug Service (IDS)	Nashville	Tennessee	37232	Recruiting
Vanderbilt University Medical Center	Nashville	Tennessee	37232	Recruiting
Vanderbilt Vaccine Research Program Laboratory	Nashville	Tennessee	37232	Recruiting
Vanderbilt Vaccine Research Program	Nashville	Tennessee	37232	Recruiting
Family Health Watch - KeyPoint Clinical Research	Dallas	Texas	75237	Recruiting
KeyPoint Clinical Research	Dallas	Texas	75240	Recruiting
North Texas Infectious Diseases Consultants, P.A	Dallas	Texas	75246	Recruiting
Cedar Health Research - Euless	Euless	Texas	76040	Recruiting
Baylor College of Medicine	Houston	Texas	77030	Recruiting
Memorial Hermann Hospital - TMC	Houston	Texas	77030	Recruiting
The University of Texas Health Science Center at Houston	Houston	Texas	77030	Recruiting
UT Physicians	Houston	Texas	77030	Recruiting
DM Clinical Research- Cyfair	Houston	Texas	77065	Recruiting
Mercury Clinical Research - Santa Clara Family Clinic	Houston	Texas	77087	Recruiting
Dynamed Clinical Research, LP d/b/a DM Clinical Research	Tomball	Texas	77375	Recruiting
Northwest Houston Heart Center	Tomball	Texas	77375	Recruiting
J. Lewis Research, Inc. / Foothill Family Clinic South	Salt Lake City	Utah	84121	Recruiting
The University of Vermont Medical Center Inc.	Burlington	Vermont	05401	Recruiting
UVM Larner College of Medicine MMG/VCT	Burlington	Vermont	05401	Recruiting
Clinical Research Partners, LLC	Richmond	Virginia	23226	Recruiting
Providence Regional Medical Center Everett	Everett	Washington	98201	Recruiting
Kaiser Permanente Washington Health Research Institute (KPWHRI)	Seattle	Washington	98101	Recruiting
University of Washington - Harborview Medical Center	Seattle	Washington	98104	Recruiting

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

Non-U.S. locations

This page focuses on the U.S. directory. The official record also lists 44 non-U.S. sites.

About this trial record page

What this page shows: Public field values for ClinicalTrials.gov record NCT07282665, 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 Sep 8, 2026 · Synced Sep 15, 2026

Open the official record

The complete protocol, eligibility criteria, and contact information for NCT07282665 live on ClinicalTrials.gov.

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