Typhoid vaccine study probes gut immunity secrets
NCT ID NCT03970304
First seen Jun 25, 2026 · Last updated Jun 27, 2026 · Updated 1 time
Summary
This study looks at how the typhoid vaccine changes the immune system and bacteria in the gut. About 87 healthy adults getting a routine colonoscopy will either receive the vaccine before the procedure, after, or not at all. Researchers will analyze blood, tissue, and stool samples to understand the body's response.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- Vivotif Typhoid Oral Vaccine (Ty21a)
- What this could lead to
- If successful, this could help design better typhoid vaccines and improve understanding of how vaccines interact with gut health.
- What could go wrong
- This is an early-stage observational study, not testing a new treatment. Results may not lead to direct health benefits or apply to broader populations.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
-
Phase 4
Runs after approval, following long-term safety and how well the treatment works in everyday use.
- Participants
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87 people
The number who actually took part.
- Started
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Oct 2013
- Expected to finish
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Aug 2027
An estimate. End dates often move.
- Lead sponsor
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Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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18 years and older
- Sex
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Anyone
- Healthy volunteers
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Accepted
You do not need to have the condition being studied to take part.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
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
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Genom att skicka in godkänner du våra Användarvillkor
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
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Universtiy of Maryland, Baltimore, Center for Vaccine Development and Global Health
Baltimore, Maryland, 21201, United States