NCT04083950

Induction of Gut Permeability by an Oral Vaccine

• Status: Active Not Recruiting
• Phase: EARLY_Phase 1
• Study type: Interventional
• Enrollment: 10 (actual)
• Sponsor: USDA, Western Human Nutrition Research Center · Federal
• Sex: Female
• Age: 18 Years – 49 Years
• Healthy volunteers: Accepted

Summary

This study evaluates the effect of an oral typhoid vaccine on disruption of the intestinal barrier and response of the immune system. Intestinal and whole-body responses will be measured in all participants before and after the vaccine.

Detailed description

The licensed Ty21a vaccine strain of S. enterica Typhi is routinely used by travelers to countries where typhoid is common. It is not known whether the vaccine causes measurable changes in intestinal permeability and whether changes in permeability are correlated with the magnitude of the vaccine response. In the current study, gut permeability will be measured in participants at baseline and after an aspirin challenge, which is known to disrupt intestinal permeability, and after the first, second, and fourth doses of a the Ty21a vaccine. Intestinal permeability will be measured using a three-sugar absorption test composed of lactulose, mannitol, and sucralose and by several plasma markers. Vaccine response will be measured by quantitating T cells and newly developed IgG-or IgA-secreting plasma cells specific for Ty21a.

Conditions

• Intestinal Permeability
• Inflammation
• Vaccine
• Typhoid Fever

Interventions

Type	Name	Description
BIOLOGICAL	Vivotif Typhoid Oral Vaccine	One capsule is swallowed on alternate days, e.g. days 15, 17, 19, and 21, for a total of 4 capsules.
DRUG	Aspirin (Positive Control)	Three tablets (325 mg aspirin in each tablet or 975 mg total) are swallowed on days 2 and 3.

Timeline

• Start date: 2019-12-04
• Primary completion: 2022-01-31
• Completion: 2026-09-30
• First posted: 2019-09-10
• Last updated: 2025-11-24

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study