C. difficile Vaccine for C. difficile Infection
Trial Summary
What is the purpose of this trial?
An antibody is a substance your body makes to fight off infection. This study will explore the safety and antibody response of a vaccine to prevent severe diarrhea caused by a germ called Clostridoides difficile (C. diff). Three new formulations of the C. diff vaccine will be used in this study, in addition to a C. diff vaccine formulation that has been studied in previous clinical trials. The purpose of this study is to understand if giving the new C. diff vaccine formulations helps people make as many antibodies as giving the previously studied C. diff vaccine formulation. The study is divided into 2 phases. Phase 1 will evaluate 3 new formulations of the C. diff vaccine and 2 dosing schedules spread out over 2 months or 6 months. The Phase 1 portion of the study is seeking participants: * who are healthy adults of 65 to 84 years of age * who have not had a C. diff infection before * who have not received a C. diff vaccine or C. diff monoclonal antibody therapy before. All participants in Phase 1 will receive study injections with active vaccine or placebo at each vaccination visit, depending on the vaccine group to which they are assigned. A placebo does not contain any active ingredients. Participants in Phase 1 will attend at least 9 study visits and will take part in the study for approximately 18 months. Based on the results of Phase 1, 1 or 2 of the new C. diff vaccine formulations will be chosen for further study in Phase 2. Phase 2 will evaluate the safety and effects of the new C. diff vaccine formulation(s) chosen in Phase 1. The Phase 2 portion of the study is seeking participants: * who are healthy adults ≥65 years of age * who have not had a C. diff infection before * who have not received a C. diff vaccine or C. diff monoclonal antibody therapy before. Phase 2 participants will receive active C. diff vaccine or placebo at each vaccination visit. Participants in Phase 2 will attend at least 6 and up to 12 study visits and will take part in the study for up to 4 years.
Do I need to stop my current medications to join the trial?
The trial protocol does not specify if you need to stop taking your current medications. However, if you are on immunosuppressive therapy or corticosteroids, you may not be eligible to participate.
What data supports the effectiveness of the C. difficile vaccine treatment?
The research highlights the importance of vaccine formulation and the use of adjuvants (substances that enhance the body's immune response to an antigen) in developing effective vaccines. This suggests that the C. difficile vaccine, if well-formulated with appropriate adjuvants, could potentially be effective in preventing infections, similar to how adjuvants have been used successfully in other vaccines.12345
How is the C. difficile vaccine treatment different from other treatments for C. difficile infection?
The C. difficile vaccine treatment is unique because it involves different formulations of a vaccine specifically designed to prevent C. difficile infections, which is different from standard treatments that typically focus on antibiotics to treat existing infections. This approach aims to prevent the infection from occurring in the first place, potentially reducing the need for antibiotics and lowering the risk of recurrence.12678
Research Team
Pfizer CT.gov Call Center
Principal Investigator
Pfizer
Eligibility Criteria
Healthy adults aged 65-84 for Phase 1, and 50-84 for Phase 2, who've never had a C. diff infection or received any C. diff vaccine or therapy. Participants must be able to follow the study plan and give informed consent. Exclusions include those on immunosuppressive therapy, involved in other investigational studies, with certain medical conditions or history of severe allergies to vaccines.Inclusion Criteria
Exclusion Criteria
Timeline
Screening
Participants are screened for eligibility to participate in the trial
Phase 1 Treatment
Evaluation of 3 new formulations of the C. diff vaccine and 2 dosing schedules over 2 or 6 months
Phase 2 Treatment
Evaluation of the safety and effects of the new C. diff vaccine formulation(s) chosen in Phase 1
Follow-up
Participants are monitored for safety and effectiveness after treatment
Treatment Details
Interventions
- C. difficile vaccine formulation 1
- C. difficile vaccine formulation 2
- C. difficile vaccine formulation 3
- C. difficile vaccine (previously studied formulation)
- Saline Placebo
Find a Clinic Near You
Who Is Running the Clinical Trial?
Pfizer
Lead Sponsor
Albert Bourla
Pfizer
Chief Executive Officer since 2019
PhD in Biotechnology of Reproduction, Aristotle University of Thessaloniki
Patrizia Cavazzoni
Pfizer
Chief Medical Officer
MD from McGill University