Clostridoides Difficile Associated Disease
Conditions
Brief summary
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.
Interventions
BIOLOGICALC.difficile vaccine
C.difficile vaccine given as an intramuscular injection
OTHERSaline Placebo
0.9% sodium chloride solution given as a intramuscular injection
Sponsors
Pfizer
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
65 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
Who Can Join the Study (Inclusion Criteria): • People with recent or future planned contact with healthcare systems, recent antibiotic exposure, or a diagnosis of certain chronic medical conditions. Who Cannot Join the Study (
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 or another serious health problem.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| The percentage of participants reporting local reactions | For 7 days after each vaccination | Injection site pain, redness, and swelling as self-reported in electronic diaries |
| Percentage of participants reporting adverse events | From each vaccination through 1 month after each vaccination | As elicited by investigator site staff |
| Percentage of participants reporting serious adverse events | From Vaccination 1 (Day 1) through 12 months after Vaccination 2 (last dose) (18 months) | As elicited by investigator site staff |
| The incidence of the first episode of medically attended and clinically meaningful primary Clostridioides difficile infection (CDI) | from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years) | First episode of medically attended and clinically meaningful primary CDI incidence per 1000 person- years of follow- up |
| The incidence of the first episode of medically attended primary CDI | from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years) | First episode of medically attended primary CDI incidence per 1000 person- years of follow- up |
| The incidence of the first episode of clinically meaningful primary CDI | from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years) | First episode of clinically meaningful primary CDI incidence per 1000 person- years of follow- up |
| The percentage of participants reporting systemic events | For 7 days after each vaccination | Fever, vomiting, fatigue, headache, muscle pain, and joint pain as self-reported in electronic diaries |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| The incidence of severe or fulminant primary CDI | from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years) | First episode of severe or fulminant primary CDI incidence per 1000 person- years of follow- up |
| The incidence of a first episode of primary CDI (any severity) | from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years) | First episode of primary CDI incidence per 1000 person- years of follow- up |
| The incidence of all CDI (primary and recurrent) | from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years) | Occurence of all C.difficile infection cases |
| The incidence of antibiotic use in the treatment of a first episode of the primary CDI | from 14 days after Vaccination 2 to the end of the surveillance period (up to approximately 3.5 years) | First episode of primary CDI with antibiotic use incidence per 1000 person- years of follow- up |
Countries
Argentina, Japan, United Kingdom, United States
Contacts
CONTACTPfizer CT.gov Call Center
STUDY_DIRECTORPfizer CT.gov Call Center
Pfizer
Outcome results
None listed