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Purpose

This is an open-label, non-randomized study. The purpose of this study is to better understand how vaccines against typhoid fever affect the normal immune system and bacteria in the intestine. Patients having standard-of-care colonoscopies will be divided into 3 groups: Group 1: Vivotif typhoid vaccination then colonoscopy; Group 2: Colonoscopy, then Vivotif typhoid vaccination, then follow-up colonoscopy; Group 3: Colonoscopy without vaccination. The Vivotif typhoid vaccine used in this study is licensed by the Food and Drug Administration (FDA) for travelers to developing countries. Volunteers will be asked to donate tissue, blood, saliva and stool samples for studying how the body responds to the typhoid vaccine.

Condition

Eligibility

Eligible Ages
Over 18 Years
Eligible Genders
All
Accepts Healthy Volunteers
Yes

Inclusion Criteria

  • Age 18 years and older - Undergoing colonoscopy for screening or surveillance for colorectal cancer at the University of Maryland - Provide written informed consent prior to initiation of any study procedures - Healthy, as defined by considered fit to undergo outpatient elective colonoscopy by the referring health care provider

Exclusion Criteria

  • Pregnancy or nursing mother - Known coagulopathy or bleeding disorder preventing mucosal biopsy - History of Crohn's disease or ulcerative colitis - Surgical removal of the ileocecal valve or any part of the small or large intestine - Allergic reaction to oral typhoid vaccine in the past - Immunosuppression from illness or treatment, including - immune-deficiency disorders such as Human Immunodeficiency Virus (HIV) or Acquired Immunodeficiency Syndrome (AIDS) - leukemia, lymphoma, or cancers - immune suppressive medications or treatments, such as corticosteroids or radiation - Receipt of any other vaccine two weeks prior to receipt of Ty21a - Positive urine pregnancy test (HCG) prior to colonoscopy or vaccination

Study Design

Phase
Phase 4
Study Type
Interventional
Allocation
Non-Randomized
Intervention Model
Parallel Assignment
Intervention Model Description
Volunteers who choose to take part in this study will receive the licensed FDA approved Oral Typhoid Vaccine (Vivotif). Volunteers also have the possibility of being a control participant who will not be vaccinated.
Primary Purpose
Basic Science
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Vaccination, Colonoscopy 		Individuals receive immunization with Vivotif typhoid vaccine prior to routine colonoscopy examination. During colonoscopy, small bowel biopsies will be obtained to examine immune responses and microbiota at the mucosal level; brushings will also be obtained.
  • Drug: Vivotif Typhoid Oral Vaccine
    The 4 doses (1 capsule each) will be administered on alternate days, e.g., days 0, 2, 4, and 7 (± 1 day) under the supervision of the study coordinator(s).
    Other names:
    • Ty21a Typhoid Oral Vaccine
Experimental
Colonoscopy, Vacciniation, Colonoscopy 		Individuals receive immunization with Vivotif typhoid vaccine after initial colonoscopy exam and specimen collection and prior to a routine follow up colonoscopy examination during which additional specimens will be collected.
  • Drug: Vivotif Typhoid Oral Vaccine
    The 4 doses (1 capsule each) will be administered on alternate days, e.g., days 0, 2, 4, and 7 (± 1 day) under the supervision of the study coordinator(s).
    Other names:
    • Ty21a Typhoid Oral Vaccine
No Intervention
Colonoscopy Without Vaccination 		Individuals do not receive immunization but consent to collection of specimens during colonoscopy. The specimens to be collected in all three groups include stool, saliva, and small bowel biopsies (terminal ileum).

More Details

Status
Active, not recruiting
Sponsor
University of Maryland, Baltimore

Study Contact

Notice

Study information shown on this site is derived from ClinicalTrials.gov (a public registry operated by the National Institutes of Health). The listing of studies provided is not certain to be all studies for which you might be eligible. Furthermore, study eligibility requirements can be difficult to understand and may change over time, so it is wise to speak with your medical care provider and individual research study teams when making decisions related to participation.