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CholeraPhase 2NCT03251495

Immunologic Responses to a Live Attenuated Oral Cholera Vaccine

A Phase 2 study testing Vaxchora in people with Cholera, run by Emory University at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The primary objective of this study is to evaluate the antibody response to the cholera vaccine, Vaxchora®, in healthy subjects. Investigators also seek to evaluate additional markers of the adaptive immune response including plasmablasts, activated B cells, memory B cells, and T cell responses in healthy subjects… Read more about this study

Who is it for?
Ages 18 to 49 yearsHealthy volunteers can take part
Conditions the study is for
Cholera
What is being tested?
Vaxchora
Could I receive a placebo?
No, everyone receives an active treatment
How many people
34 participants
Where
1 siteUnited States
Study dates
29 Aug 2017to 6 Nov 2025
Phase
Phase 2
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 49 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Capable of informed consent and provision of written informed consent before any study procedures
  • Capable of attending all study visits according to the study schedule
  • Are in good health, as determined by medical history and targeted physical exam related to this history
  • Female subjects of childbearing age must have a negative urine pregnancy test before study vaccination, and must use two forms of contraception to avoid pregnancy within one month of Vaxchora administration

Who cannot join

  • Have an acute illness within 72 hours before vaccination
  • Have any acute or chronic medical condition that, in the opinion of the principal investigator, would make vaccination unsafe or interfere with the evaluation of immune response to study vaccination
  • Have a suppressed immune system as a result of illness, immunosuppressive medication, chemotherapy, or radiation therapy within 3 years prior to study vaccination
  • Have taken oral or parenteral corticosteroids of any dose within 30 days before study vaccination
  • Reside with individuals under the age of 2 or with an immunocompromised individuals
  • Have a known history of autoimmune disease
Show all 27Show fewer
  • Have a history of Guillain-Barre Syndrome
  • Have plans to receive any vaccine from 28 days prior to study vaccination until Day 29
  • Has previously received a cholera vaccine or have a known history of V. Cholerae.
  • Have donated blood or blood products within 56 days before study vaccination, plan to donate blood at any time during the 56-day duration of subject study participation, or plan to donate blood within 56 days after the last blood draw
  • Have known hypersensitivity or allergy to any component of the vaccine or history of anaphylaxis with a vaccine or vaccine component
  • Have allergy to tetracycline and/or ciprofloxacin
  • Are pregnant or breastfeeding or plan to within one month of vaccination
  • Traveled to a cholera endemic area and had traveler's diarrhea in the previous 5 years
  • Have abnormal stool pattern (fewer than 3 stools/ week or greater than 2 stools/ day) or regular use of laxatives in the last 6 months
  • Have current or recent antibiotic use in the past 14 days
  • Are healthcare workers who have direct contact with patients who are immunocompromised, have unstable medical conditions, or are under the age of 2
  • Are childcare caregivers who have direct contact with children who are 2 years or younger
  • Are employed in the food industry
  • Have received any vaccine within the previous 21 days
  • History of bleeding disorders or current use of warfarin, aspirin, heparin, nonsteroidal anti-inflammatory drugs (NSAIDs) or other blood thinner/ anticoagulant medications in the past week for subjects undergoing intestinal biopsies.
  • Use of benzodiazepines or narcotics for subjects undergoing intestinal biopsies 4 weeks prior to the procedure
  • Any contraindications to endoscopy/concerns of the anesthesiologist for subjects who agree for esophagogastroduodenoscopy (EGD)/biopsies
  • Body mass index (BMI) > 35 kg/m^2
  • Have a diagnosis of any small bowel disease. This includes but is not limited to inflammatory bowel disease (e.g., Crohn's disease, ulcerative colitis, indeterminate colitis, or microscopic colitis), small bowel obstruction, celiac disease, h/o small bowel resection, small bowel lymphoma, Whipple's disease, primary intestinal lymphangiectasis, abdominal radiation.
  • Current medications for the treatment of gastroesophageal reflux disease (GERD) or dyspepsia
  • History of Helicobacter pylori (H. pylori) infection

Trial locations and contacts

1 site in 1 country.

United States1 site

  • The Hope Clinic of Emory University

    Atlanta, Georgia, 30030

Other trials in United States

About this study

The primary objective of this study is to evaluate the antibody response to the cholera vaccine, Vaxchora®, in healthy subjects.

Investigators also seek to evaluate additional markers of the adaptive immune response including plasmablasts, activated B cells, memory B cells, and T cell responses in healthy subjects receiving cholera vaccine, produce monoclonal antibodies against cholera, and evaluate the safety and reactogenicity in healthy subjects receiving cholera vaccine.

Read the detailed description

Vibrio cholerae causes an acute diarrheal disease responsible for more than 100,000 deaths and affects an estimated 3 to 5 million people annually. Recent epidemics in Haiti and Africa illustrate the continued reach of this pathogen. Across the globe, one billion people lack access to safe drinking water and are vulnerable to cholera. The increasing disease burden, and emergence of more virulent strains, suggest that more aggressive approaches to preventing cholera are needed. This includes renewed efforts to understand the mechanism of protective immunity against cholera and to improve the protective efficacy of current cholera vaccines.

Vaxchora is a live attenuated cholera vaccine that protects against some cholera strains. It has been approved by the FDA since June 2016. Since October, 2016, this vaccine has been recommended for certain travelers 18 through 64 years of age going to cholera-affected areas. The purpose of this study is to look at the immune responses to the FDA approved cholera vaccine (Vaxchora®).

This study aims to enroll 50 participants who will receive the Vaxchora live cholera vaccine, of whom 30 will undergo two procedures for small intestinal biopsies: one at screening and the other post vaccination (25 participants at Day 29 and 5 participants at day 90) by an upper endoscopy biopsy (EGD).

Conditions
Cholera
Being tested
Vaxchora
Keywords
Vaccination, Contagious Diseases, Tropical Medicine, Infectious Diseases
Medical subject headings
Cholera, Communicable Diseases

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • VaxchoraDrug

    Vaxchora is a live attenuated cholera vaccine that provides immunity against V. cholerae serogroup O1. Participants will receive one single oral dose of 100 mL.

Study groups in NCT03251495
Study groupRoleWhat they receive
Vaxchora VaccinationExperimentalHealthy participants will receive a single dose of oral live cholera vaccine.
Receives: Drug: Vaxchora

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Level of Antibody Titers in Serum

    Antibody response is evaluated as the level of antibody titers in serum. Higher vibriocidal antibody titers indicate greater protection against cholera.

    Measured: Day 1 (pre-vaccination), Day 29

Secondary outcomes (7)

  1. Plasmablast Levels

    Plasmablasts are collected via blood draw and isolated and assessed for counts by the study team.

    Measured: Day 1 (pre-vaccination), Day 8, Day 29

  2. Activated B Cell Levels

    Activated B cells are collected via blood draw and isolated and assessed for counts by the study team.

    Measured: Day 1 (pre-vaccination), Day 8, Day 29

  3. Memory B Cell Levels

    Memory B cells are collected via blood draw and isolated and assessed for counts by the study team. The level of memory B cells is evaluated as the percentage of antigen specific immunoglobulin (Ig) secreting cells divided by the total Ig secreting cells.

    Measured: Day 1 (pre-vaccination), Day 29

  4. Number of Monoclonal Antibodies Produced Per Participant

    The number of antigen-specific monoclonal antibodies (mAbs) was assessed in a subset of participants on Day 8 post-vaccination. Peripheral blood mononuclear cells (PBMCs) were isolated, and antigen-specific plasmablasts were single-cell sorted using fluorescently labeled V. cholerae antigens (e.g., CTB and LPS). Paired immunoglobulin heavy and light chain variable regions were amplified by RT-PCR, cloned into expression vectors, and expressed in mammalian cells. The number of unique antigen-specific monoclonal antibodies was determined by binding assays (e.g., ELISA).

    Measured: Day 8

  5. Number of Cholera Toxin B (CTB) Specific Monoclonals and Lipopolysaccharide (LPS) Specific Monoclonal Antibodies Per Participant

    The monoclonal antibodies obtained were characterized as cholera toxin B (CTB) specific monoclonals and lipopolysaccharide (LPS) specific monoclonals. The characterization of monoclonal antibodies against V. cholerae is assessed in a subset of participants.

    Measured: Day 8

  6. Number of Adverse Events

    The number of solicited and unsolicited adverse events were collected.

    Measured: Up to Day 8, Up to Day 29

  7. Number of Serious Adverse Events

    The number of serious adverse events were collected during the duration of the study.

    Measured: Up to Day 365

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted16 Aug 2017
  2. Study start29 Aug 2017
  3. Primary completion10 Dec 2024
  4. Study completion6 Nov 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Prevention
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
34 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03251495
Sponsor's protocol ID
IRB00097012
Other IDs
R01AI137127
Status last verified
Feb 2026
First submitted
14 Aug 2017
Last updated
13 Feb 2026
Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No

Publications

  • Adekunle O, Dretler A, Kauffman RC, Cho A, Rouphael N, Wrammert J. Longitudinal analysis of human humoral responses after vaccination with a live attenuated V. cholerae vaccine. PLoS Negl Trop Dis. 2021 Sep 3;15(9):e0009743. doi: 10.1371/journal.pntd.0009743. eCollection 2021 Sep.

    PubMed 34478460

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Vaxchora in people with Cholera, run by Emory University at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 27 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 13 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 13 Feb 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Level of Antibody Titers in Serum (time frame: Day 1 (pre-vaccination), Day 29). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT03251495, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Feb 2026.

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