CVD 37000: Immunity and Microbiome Studies at Intestinal and Systemic Sites in Ty21a Vaccinated Adults

University of Maryland Baltimore (UMB)

Status and phase: Active, not recruiting; Phase 4

Conditions: Typhoid Vaccination

Treatments: Drug: Vivotif Typhoid Oral Vaccine

Study type: Interventional

Funder types: Other

Identifiers

NCT03970304

HP-00056321

Details and patient eligibility

About

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.

Enrollment: 87 patients

Sex: All

Ages: 18+ years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Basic Science

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

---

87 participants in 3 patient groups

Vaccination, Colonoscopy

Experimental group

Description:

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.

Treatment:

Drug: Vivotif Typhoid Oral Vaccine

Colonoscopy, Vacciniation, Colonoscopy

Experimental group

Description:

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.

Treatment:

Drug: Vivotif Typhoid Oral Vaccine

Colonoscopy Without Vaccination

No Intervention group

Description:

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).