Clinical Research Studies

The purpose of this trial is to evaluate the safety and immune effects of an investigational vaccine in healthy volunteers ages 65 and older. This vaccine is being studied to potentially prevent severe diarrhea caused by a bacterium called Clostridioides difficile (C. diff).

In U.S. hospitals, C. diff is the main cause of infectious diarrhea and can lead to severe infections or even death. Although people of all ages are at risk for C. diff infection, adults 65 years of age and older are at an increased risk. Thus, researchers are designing a C. diff vaccine to help prevent infections for everyone, especially for vulnerable groups such as older adults.

The investigational C. diff vaccine that participants will be given in this study has already been given to hundreds of people in previous research studies.

If you are eligible and agree to participate, you will be randomly assigned to 1 of 6 groups. You will receive up to 4 injections during your study participation.

Depending on the group you are randomized to, you would participate over either a period of 7 months (4 in-person study visits) or 4 years (12 in-person study visits).

You may receive up to $150 for each in-person study visit and may be reimbursed for travel costs up to $51. Also, if you choose to have an additional and optional blood sample collected at three visits, you will be compensated an additional $75 at each of these visits.