NCT03705585 · University of Maryland, Baltimore
CVD 38000: Study of Responses to Vaccination With Typhoid and/or Cholera
What this study is about
This is an where both patients and doctors know the treatment given, non-randomly assigned study. The purpose of this study is to better understand how vaccines against typhoid fever and cholera affect the normal immune system and bacteria in the intestine.
View original scientific description
This is an open-label, non-randomized study. The purpose of this study is to better understand how vaccines against typhoid fever and cholera affect the normal immune system and bacteria in the intestine. Patients having standard-of-care endoscopies (colonoscopy and/or esophagogastroduodenoscopy (EGD)) will be divided into 3 groups: Group 1: Vivotif typhoid vaccination and/or Vaxchora cholera vaccination then endoscopy Group 2: Endoscopy, then Vivotif typhoid vaccination and/or Vaxchora cholera vaccination, then follow-up endoscopy Group 3: Endoscopy without vaccination. Both vaccines used in this study are 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 and/or cholera vaccine.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- 1\. Age 18 years and older
- 2\. Already scheduled to undergo an EGD or colonoscopy for screening, surveillance, or a medically-indicated work-up at the University of Maryland Medical Center (main campus or Midtown)
- 3\. Able to provide written informed consent prior to initiation of any study procedures
- 4\. Healthy, as defined by considered fit to undergo outpatient elective EGD/colonoscopy by the evaluating health care provider
Exclusion criteria
- 1\. Pregnancy or nursing mother
- 2\. Known coagulopathy or bleeding disorder preventing mucosal biopsy
- 3\. History of Crohn's disease or ulcerative colitis
- 4\. For Subjects undergoing lower endoscopy (colonoscopy) only: Surgical removal of the ileocecal valve or any part of the small or large intestine (non-complicated appendectomy will be considered eligible)
- 5\. Allergic reaction to oral typhoid or cholera vaccine in the past
- 6\. Immunosuppression from illness or treatment, including
- immune-deficiency disorders such as Human Immunodeficiency Virus (HIV) or Acquired Immunodeficiency Syndrome (AIDS)
- leukemia, lymphoma, or cancers (localized non-melanoma skin cancers which are deemed inactive should be considered eligible)
- 7\. Receipt of any other vaccine two weeks prior to receipt of Ty21a or CVD 103-HgR
- 8\. Positive urine pregnancy test (HCG) prior to colonoscopy or vaccination
Where
- Baltimore, Maryland
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 19, 2025 · Source of record for eligibility and locations