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

NCT ID: NCT07282665

Last Updated: 2026-01-12

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

PHASE3

Total Enrollment

32000 participants

Study Classification

INTERVENTIONAL

Study Start Date

2025-12-10

Study Completion Date

2029-06-07

Brief Summary

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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 works or clearly doesn't. 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 clinical 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.

Detailed Description

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Conditions

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Clostridioides Difficile Associated Disease

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

PREVENTION

Blinding Strategy

TRIPLE

Participants Investigators Outcome Assessors

Study Groups

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C.difficile vaccine

Novel vaccine formulation

Group Type EXPERIMENTAL

C.difficile vaccine

Intervention Type BIOLOGICAL

C.difficile vaccine given as an intramuscular injection

Saline Placebo

Group Type OTHER

Saline Placebo

Intervention Type OTHER

0.9% sodium chloride solution given as a intramuscular injection

Interventions

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C.difficile vaccine

C.difficile vaccine given as an intramuscular injection

Intervention Type BIOLOGICAL

Saline Placebo

0.9% sodium chloride solution given as a intramuscular injection

Intervention Type OTHER

Eligibility Criteria

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Inclusion Criteria

• People with recent or future planned contact with healthcare systems or who have recently received antibiotics.

Exclusion Criteria

* Anyone who has had CDI before.
* Anyone who has had surgery to remove part of their small or large intestine.
* Anyone who often has diarrhea (meaning three or more loose stools in a day, more than once a month).
* Anyone who has already received a vaccine or special antibody treatment for C. difficile.
* Anyone who has had a serious allergic reaction to a vaccine or to any part of the study vaccines.
* Anyone who might not respond well to the vaccine because their immune system is weak (either from a disease or from treatment).
* Anyone with cancer that has spread, kidney failure, or another serious health problem.
Minimum Eligible Age

65 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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Pfizer

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Pfizer CT.gov Call Center

Role: STUDY_DIRECTOR

Pfizer

Locations

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North Alabama Research Center

Athens, Alabama, United States

Site Status RECRUITING

Lakeview Clinical Research

Guntersville, Alabama, United States

Site Status RECRUITING

Medical Affiliated Research Center

Huntsville, Alabama, United States

Site Status NOT_YET_RECRUITING

Epic Medical Research-Sun City

Sun City, Arizona, United States

Site Status RECRUITING

Applied Research Center of Arkansas

Little Rock, Arkansas, United States

Site Status RECRUITING

Velocity Clinical Research, San Bernardino

San Bernardino, California, United States

Site Status RECRUITING

Carbon Health - San Mateo - Hillsdale Mall

San Mateo, California, United States

Site Status NOT_YET_RECRUITING

Med Partners, Inc. dba Premiere Medical Center of Burbank, Inc.

Toluca Lake, California, United States

Site Status NOT_YET_RECRUITING

Diablo Clinical Research, Inc.

Walnut Creek, California, United States

Site Status RECRUITING

GW Vaccine Research Unit

Washington D.C., District of Columbia, United States

Site Status NOT_YET_RECRUITING

The GW Medical Faculty Associates

Washington D.C., District of Columbia, United States

Site Status NOT_YET_RECRUITING

Proactive Clinical Research,LLC

Fort Lauderdale, Florida, United States

Site Status RECRUITING

Indago Research & Health Center, Inc

Hialeah, Florida, United States

Site Status RECRUITING

Clinical Neuroscience Solutions, Inc. dba CNS Healthcare

Jacksonville, Florida, United States

Site Status NOT_YET_RECRUITING

M3 Wake Research - Lake City

Lake City, Florida, United States

Site Status NOT_YET_RECRUITING

South Florida Research Organization

Medley, Florida, United States

Site Status RECRUITING

Care Research Inc

Miami, Florida, United States

Site Status NOT_YET_RECRUITING

Entrust Clinical Research

Miami, Florida, United States

Site Status NOT_YET_RECRUITING

Charisma Medical and Research Center

Miami Lakes, Florida, United States

Site Status RECRUITING

Palm Springs Community Health Center

Miami Lakes, Florida, United States

Site Status NOT_YET_RECRUITING

Innovation Medical Research Center

Palmetto Bay, Florida, United States

Site Status NOT_YET_RECRUITING

Angels Clinical Research Institute

Tampa, Florida, United States

Site Status NOT_YET_RECRUITING

Centricity Research Columbus Georgia Multispecialty

Columbus, Georgia, United States

Site Status NOT_YET_RECRUITING

Velocity Clinical Research, Savannah

Savannah, Georgia, United States

Site Status NOT_YET_RECRUITING

DM Clinical Research - Chicago

Melrose Park, Illinois, United States

Site Status NOT_YET_RECRUITING

Accellacare - McFarland

Ames, Iowa, United States

Site Status NOT_YET_RECRUITING

McFarland Clinic, PC

Ames, Iowa, United States

Site Status NOT_YET_RECRUITING

Velocity Clinical Research, Sioux City

Sioux City, Iowa, United States

Site Status NOT_YET_RECRUITING

AMR Clinical

Newton, Kansas, United States

Site Status NOT_YET_RECRUITING

Revive Research Institute, Inc.

Southfield, Michigan, United States

Site Status RECRUITING

DM Clinical Research - Detroit

Southfield, Michigan, United States

Site Status RECRUITING

Sundance Clinical Research

St Louis, Missouri, United States

Site Status NOT_YET_RECRUITING

Velocity Clinical Research, Grand Island

Grand Island, Nebraska, United States

Site Status RECRUITING

Velocity Clinical Research, Omaha

Omaha, Nebraska, United States

Site Status NOT_YET_RECRUITING

Renown Center for Advanced Medicine

Reno, Nevada, United States

Site Status NOT_YET_RECRUITING

Renown Regional Medical Center

Reno, Nevada, United States

Site Status NOT_YET_RECRUITING

University Health

Reno, Nevada, United States

Site Status NOT_YET_RECRUITING

South Jersey Infectious Disease

Somers Point, New Jersey, United States

Site Status RECRUITING

Albuquerque Clinical Trials, Inc.

Albuquerque, New Mexico, United States

Site Status NOT_YET_RECRUITING

Upstate Global Health Institute

East Syracuse, New York, United States

Site Status NOT_YET_RECRUITING

Rochester Clinical Research, LLC

Rochester, New York, United States

Site Status NOT_YET_RECRUITING

Accellacare - Cary

Cary, North Carolina, United States

Site Status NOT_YET_RECRUITING

Medication Management

Greensboro, North Carolina, United States

Site Status NOT_YET_RECRUITING

Accellacare - Hickory

Hickory, North Carolina, United States

Site Status RECRUITING

Accellacare - Raleigh

Raleigh, North Carolina, United States

Site Status NOT_YET_RECRUITING

Accellacare - Salisbury

Salisbury, North Carolina, United States

Site Status NOT_YET_RECRUITING

Accellacare - Wilmington

Wilmington, North Carolina, United States

Site Status NOT_YET_RECRUITING

Accellacare - Winston-Salem

Winston-Salem, North Carolina, United States

Site Status NOT_YET_RECRUITING

CTI Clinical Research Center

Cincinnati, Ohio, United States

Site Status RECRUITING

Kaiser Permanente Center for Health Research

Portland, Oregon, United States

Site Status NOT_YET_RECRUITING

Capital Area Research, LLC

Camp Hill, Pennsylvania, United States

Site Status NOT_YET_RECRUITING

DM Clinical Research - Philadelphia

Philadelphia, Pennsylvania, United States

Site Status NOT_YET_RECRUITING

Walker Family Care

Little River, South Carolina, United States

Site Status RECRUITING

Trial Management Associates, LLC

Myrtle Beach, South Carolina, United States

Site Status NOT_YET_RECRUITING

Trial Management Associates

Myrtle Beach, South Carolina, United States

Site Status NOT_YET_RECRUITING

Velocity Clinical Research, Spartanburg

Spartanburg, South Carolina, United States

Site Status NOT_YET_RECRUITING

New Phase Research and Development

Knoxville, Tennessee, United States

Site Status RECRUITING

Clinical Neuroscience Solutions Inc.

Memphis, Tennessee, United States

Site Status NOT_YET_RECRUITING

Family Health Watch - KeyPoint Clinical Research

Dallas, Texas, United States

Site Status NOT_YET_RECRUITING

KeyPoint Clinical Research

Dallas, Texas, United States

Site Status NOT_YET_RECRUITING

Cedar Health Research - Euless

Euless, Texas, United States

Site Status NOT_YET_RECRUITING

DM Clinical Research- Cyfair

Houston, Texas, United States

Site Status RECRUITING

Mercury Clinical Research - Santa Clara Family Clinic

Houston, Texas, United States

Site Status RECRUITING

Dynamed Clinical Research, LP d/b/a DM Clinical Research

Tomball, Texas, United States

Site Status NOT_YET_RECRUITING

Northwest Houston Heart Center

Tomball, Texas, United States

Site Status RECRUITING

J. Lewis Research, Inc. / Foothill Family Clinic South

Salt Lake City, Utah, United States

Site Status RECRUITING

Clinical Research Partners, LLC

Richmond, Virginia, United States

Site Status NOT_YET_RECRUITING

University of Washington - Harborview Medical Center

Seattle, Washington, United States

Site Status NOT_YET_RECRUITING

Equipo Ciencia

Buenos Aires, Buenos Aires F.D., Argentina

Site Status NOT_YET_RECRUITING

Sanatorio Sagrado Corazón

Buenos Aires, , Argentina

Site Status NOT_YET_RECRUITING

Newquay Health Centre

Newquay, Cornwall, United Kingdom

Site Status NOT_YET_RECRUITING

Royal Devon & Exeter Hospital

Exeter, Devon, United Kingdom

Site Status NOT_YET_RECRUITING

Knowle House Surgery

Plymouth, Devon, United Kingdom

Site Status NOT_YET_RECRUITING

Brunel Medical Practice (St Marychurch)

Torquay, Devon, United Kingdom

Site Status NOT_YET_RECRUITING

Panthera Biopartners - Preston

Preston, England, United Kingdom

Site Status NOT_YET_RECRUITING

Synexus Scotland Clinical Research Centre

Glasgow, Glasgow CITY, United Kingdom

Site Status NOT_YET_RECRUITING

Panthera Biopartners - Manchester

Rochdale, Manchester, United Kingdom

Site Status NOT_YET_RECRUITING

Panthera Clinic - York

York, North Yorkshire, United Kingdom

Site Status NOT_YET_RECRUITING

Lakeside Surgery

Corby, Northamptonshire, United Kingdom

Site Status NOT_YET_RECRUITING

Panthera Biopartners - Glasgow

Glasgow, Scotland, United Kingdom

Site Status NOT_YET_RECRUITING

Synexus Midlands Clinical Research Centre

Birmingham, , United Kingdom

Site Status NOT_YET_RECRUITING

Synexus Manchester Clinical Research Centre

Manchester, , United Kingdom

Site Status NOT_YET_RECRUITING

Panthera Biopartners - Sheffield

Sheffield, , United Kingdom

Site Status NOT_YET_RECRUITING

Countries

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United States Argentina United Kingdom

Central Contacts

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Pfizer CT.gov Call Center

Role: CONTACT

1-800-718-1021

Related Links

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https://pmiform.com/clinical-trial-info-request?StudyID=C4771002

To obtain contact information for a study center near you, click here.

Other Identifiers

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C4771002

Identifier Type: -

Identifier Source: org_study_id

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