A Phase 2 interventional study of Vaxchora in Cholera, sponsored by Emory University. Completed at 1 site in United States. Open to participants aged 18 Years to 49 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-02-13.
Sponsored by Emory University · Phase 2, Interventional, and Prevention
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.
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).
83 studies on the registry are indexed under Cholera; 16 are open to participants now.
This study's enrollment of 34 is below the median of 262 across 72 interventional studies indexed under Cholera.
Browse Cholera studies →Emory University is the lead sponsor of 1,405 studies on the registry; 225 are open to participants now.
Of its 237 completed or terminated interventional studies of FDA-regulated products, 178 (75%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Healthy participants will receive a single dose of oral live cholera vaccine.
Drug: Vaxchora
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.
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.
Time frame: Day 1 (pre-vaccination), Day 29
Plasmablast Levels
Plasmablasts are collected via blood draw and isolated and assessed for counts by the study team.
Time frame: Day 1 (pre-vaccination), Day 8, Day 29
Activated B Cell Levels
Activated B cells are collected via blood draw and isolated and assessed for counts by the study team.
Time frame: Day 1 (pre-vaccination), Day 8, Day 29
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.
Time frame: Day 1 (pre-vaccination), Day 29
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).
Time frame: Day 8
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.
Time frame: Day 8
Number of Adverse Events
The number of solicited and unsolicited adverse events were collected.
Time frame: Up to Day 8, Up to Day 29
Number of Serious Adverse Events
The number of serious adverse events were collected during the duration of the study.
Time frame: Up to Day 365
Participants were recruited at The Hope Clinic of Emory University in Atlanta, Georgia, USA. Participant enrollment began August 29, 2017 and follow up for the Day 29 study visit concluded on December 10, 2024.
| Milestone | Vaxchora Vaccination |
|---|---|
| Started | 34 |
| Completed | 28 |
| Not completed | 6 |
| Withdrew: Lost to follow-up | 4 |
| Withdrew: Withdrawal by subject | 2 |
Antibody response is evaluated as the level of antibody titers in serum. Higher vibriocidal antibody titers indicate greater protection against cholera.
| Vibriocidal antibody titer | Vaxchora Vaccination |
|---|---|
| Day 1, pre-vaccination | 76 ± 80.9 |
| Day 29 | 2671 ± 2552.8 |
Plasmablasts are collected via blood draw and isolated and assessed for counts by the study team.
| percent of CD19+ lymphocytes | Vaxchora Vaccination |
|---|---|
| Day 1, pre-vaccination | 2.0 ± 1.9 |
| Day 8 | 5.3 ± 5.5 |
| Day 29 | 1.2 ± 0.81 |
Activated B cells are collected via blood draw and isolated and assessed for counts by the study team.
| percent of CD19+ lymphocytes | Vaxchora Vaccination |
|---|---|
| Day 1, pre-vaccination | 0.8 ± 0.6 |
| Day 8 | 0.7 ± 0.5 |
| Day 29 | 0.7 ± 0.6 |
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.
| % antigen specific cells/total cells | Vaxchora Vaccination |
|---|---|
| Day 1, pre-vaccination | NA ± NA |
| Day 29 | NA ± NA |
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).
| monoclonal antibodies (mAbs) | Vaxchora Vaccination |
|---|---|
| Number of Monoclonal Antibodies Produced Per Participant | 24.83 ± 6.80 |
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.
| monoclonal antibodies (mAbs) | Vaxchora Vaccination |
|---|---|
| Cholera Toxin B (CTB) specific monoclonals | 1.67 ± 2.34 |
| Lipopolysaccharide (LPS) specific monoclonals | 9.17 ± 7.73 |
The number of solicited and unsolicited adverse events were collected.
| count of events | Vaxchora Vaccination |
|---|---|
| Days 1 - 8 | 77 |
| Days 9 - 29 | 1 |
The number of serious adverse events were collected during the duration of the study.
| count of events | Vaxchora Vaccination |
|---|---|
| Up to Day 29 | 0 |
| Day 30 to Day 365 | 1 |
Collected over Information on adverse events was collected beginning at the baseline assessment and continued through Day 29 (for a total of 29 days). Information on serious adverse events was collected up to Day 365 (for a total of 365 days).. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| Vaxchora Vaccination | 0/34 (0%) | 1/34 (2.9%) | 19/34 (55.9%) |
| Event | Vaxchora Vaccination |
|---|---|
| Hypertension urgencyCardiac disorders | 1/34 |
| Event | Vaxchora Vaccination |
|---|---|
| HeadacheGeneral disorders | 11/34 |
| DiarrheaGastrointestinal disorders | 9/34 |
| FatigueGeneral disorders | 8/34 |
| Nausea/vomitingGastrointestinal disorders | 6/34 |
| Abdominal painGastrointestinal disorders | 6/34 |
| Lack of appetiteGeneral disorders | 2/34 |
| TachycardiaCardiac disorders | 1/34 |
| BruiseSkin and subcutaneous tissue disorders | 1/34 |
| GastritisGastrointestinal disorders | 1/34 |
| Age, Categorical(Participants) | Vaxchora Vaccination |
|---|---|
| <=18 years | 0 |
| Between 18 and 65 years | 34 |
| >=65 years | 0 |
| Age, Continuous(years) | Vaxchora Vaccination |
|---|---|
| Mean | 33.9 ± 8.5 |
| Sex/Gender, Customized(Participants) | Vaxchora Vaccination |
|---|---|
| Female | 17 |
| Male | 13 |
| Unknown/Not reported | 4 |
| Ethnicity (NIH/OMB)(Participants) | Vaxchora Vaccination |
|---|---|
| Hispanic or Latino | 1 |
| Not Hispanic or Latino | 33 |
| Unknown or Not Reported | 0 |
| Race (NIH/OMB)(Participants) | Vaxchora Vaccination |
|---|---|
| American Indian or Alaska Native | 1 |
| Asian | 1 |
| Native Hawaiian or Other Pacific Islander | 0 |
| Black or African American | 11 |
| White | 20 |
| More than one race | 1 |
| Unknown or Not Reported | 0 |
| Region of Enrollment(Participants) | Vaxchora Vaccination |
|---|---|
| United States | 34 |
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Studies of the drug tested here: Vaxchora