Status unknownNCT05453253Updated Mar 7, 2023

Immune Response to a Delayed Second Dose of Oral Cholera Vaccine

A Phase 4 interventional study of Delayed second dose of oral cholera vaccine, Euvichol-Plus and Oral cholera vaccine, Euvichol-Plus, according to manufacturer notice in Cholera and Vibrio Cholerae Infection, sponsored by Epicentre. Status unknown at 1 site in Guinea. Open to participants aged 1 Year to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2023-03-07.

Sponsored by Epicentre · Phase 4, Interventional, and Prevention

The sponsor has not verified this record recently (last verified Mar 2023), so the status shown — last known as Active, not recruiting — may be out of date.

Phase: Phase 4
Study type: Interventional
Enrollment: 456
Allocation: Randomized
Ages: 1 Year to 40 Years
Sex: All

Study summary

Immune response to a delayed second dose of oral cholera vaccine

A randomized, controlled, non-inferiority immunogenicity trial in Conakry, The Republic of Guinea

Read the detailed description

Manufacturers of oral cholera vaccine (OCV) recommend a 7- or 14-days interval between two doses. To carry out two rounds of mass vaccination within this delay is not always feasible and many campaigns implemented to date have used a longer interval. Recent evidence indicates that an extended interval between OCV doses might result in equivalent seroconversion rates and in an improved boosting of mucosal immune responses following the second dose. To guide future OCV vaccination campaigns and improve cholera prevention, it is important to demonstrate the non-inferior immune response of an extended interval between OCV doses.

The Investigators aim to demonstrate the non-inferiority of the humoral immune response between individuals receiving a second Euvichol-Plus® pre-qualified OCV dose either 6 or 12 months after the initial dose and individuals receiving a second pre-qualified OCV dose 14 days after the initial dose. The humoral immune response will be assessed as the post-vaccination titer of serum vibriocidal antibodies at 14 days post-2nd dose vaccination. Secondary outcomes include the comparison of the overall rate of vibriocidal seroconversion 14 days after either the first or the second vaccine dose. A subsample of individuals ≥ 18 years will have additional serological evaluation to characterize the kinetics of their antibody responses up to 6 months after the second OCV vaccine dose. Although the vaccine has an established and safe profile, occurrence of adverse events and serious adverse events following vaccination will be assessed (safety evaluation).

The study will be an open-label, randomized, controlled, non-inferiority immunogenicity trial comparing the humoral immune responses to OCV in two interventions arms (6 and 12 months interval between OCV doses) compared with a control arm (standard 14-day interval). In each arm, the aim is to recruit 152 individuals aged 1 to 40 year-old eligible for OCV vaccination from the general population (ie. 456 individuals in total). The sub-sample allowing characterizing the kinetics of the humoral response up to 6 months after the administration of the second dose will include 38 participants in each intervention and control arm, among the participants aged ≥ 18 years. In total, 456 individuals will be recruited.

The study will be conducted in Conakry, in the Republic of Guinea. Participants will be primarily enrolled in the commune of Dixinn on a voluntary basis. All participants in the intervention and control arms will be invited to a first visit for assessment of eligibility and 1st OCV dose, followed by a visit 14 days after the 1st OCV dose for blood sampling. According to the study arm, the 2nd OCV dose will be administered at 14 days, 6 months or 1 year after the 1st dose and will be followed by a visit 14 days later for blood sampling. Participants in the sub-study will be invited to additional study visits (up to twelve visits in total) for blood sampling. At each visit, blood will be drawn for immunologic analyses.

Conditions studied

Cholera
Vibrio Cholerae Infection

Browse trials for

Cholera 79

Keywords

Delayed vaccine
Cholera
non-inferiority

In context

Cholera

79 studies on the registry are indexed under Cholera; 11 are open to participants now.

This study's enrollment of 456 is above the median of 292 across 68 interventional studies indexed under Cholera.

Browse Cholera studies →

Lead sponsor

Epicentre is the lead sponsor of 48 studies on the registry; 5 are open to participants now.

Counted across the registry records on this site, refreshed daily.

Who can participate

Ages eligible: 1 Year to 40 Years
Sexes eligible: All
Accepts healthy volunteers: Yes

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.

Inclusion criteria

Any healthy individual ≥ 1 year-old and younger than 40 years old , eligible for OCV vaccination (not suffering from a medical condition that contraindicates vaccination, i.e. any acute illness, including acute gastrointestinal illness or acute febrile illness).
Living in the study area with no plan to move away over the study period (up to 18 months).
Who provided written informed consent or whose representative (mother, father or main caretaker) provided written informed consent in case of individuals younger than 18 years. A written assent will also be obtained from adolescents (10-17 years)
An individual who (or whose mother, father or main caretaker) is, based on the judgment of the investigator, capable of complying with the study requirements.

Exclusion criteria

Exclusion Criteria:

Known history of hypersensitivity reactions to other vaccines.
Individual acutely ill or with signs of infection at the time of enrolment (e.g. fever > 38⁰C)
Gastrointestinal symptoms including nausea, vomiting, diarrhea, or decreased appetite within 24 hours prior to study initiation .
Diarrhea, administration of antidiarrheal drugs or antibiotics to treat diarrhea or abdominal pain either lasting 2 weeks or longer within 6 months prior to study initiation, or occurring during the week before study initiation.
Other vaccination within 1 week prior to study initiation or planned vaccination during the following month after vaccine intake .
Participation in another trial with investigational product within 1 month prior to study initiation.
Pregnant (as determined by a urine test on the day of each vaccination) or lactating women, women of reproductive age planning pregnancy before the end of the study period (up to minimum 18 months).
An individual thought to have difficulty participating in the study due to other reasons (such as mental disorders, alcohol or drug intoxication), based on the judgment of the investigator.
History of cholera vaccination or history of cholera as diagnosed by a medical person in a health facility (with or without laboratory confirmation).
Severe chronic diseases or medical conditions, based on the medical judgment of the investigator, such as known low hemoglobin level or symptomatic anemia, severe acute malnutrition, chronic infection (e.g. tuberculosis), sequel of poliomyelitis, immunodeficiency due to symptomatic HIV/AIDS.
Based on participant verbal reporting of the participant at inclusion, more than two persons in households \<5 persons or three participants in households ≥ 5 persons.
Thrombocytopenia or bleeding disorders or other known contraindication to venipuncture. Severe medical condition that contraindicates vaccination. In particular, a) known history of immune function disorders; or b) current use of steroids cytotoxic drugs, immunosuppressant, immune modifying drug, Prednisolone, Azathioprine, Cyclosporin, Interferon, G-CSF, Tacrolimus, Everolimus, Sirolimus; or c) known active malignancy with the exception of adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer, adequately treated Stage I cancer from which the patient is currently in complete remission, or any other cancer from which the patient has been disease-free for 5 years; or d) known uncompensated NYHA Class 3 or 4 congestive heart failure; or e) known myocardial infarction within the previous 6 months; or f) known neurological and/or psychiatric disorder.

Study design

Phase: Phase 4
Primary purpose: Prevention
Allocation: Randomized
Intervention model: Parallel assignment
Masking: None (open label)
Enrollment: 456 participants (actual)

Study arms

Experimental
interventional 6 months interval between OCV doses
This intervention arm will modify the recommended interval for administration of the second Euvichol-Plus®, which will be extended to 6 months.
Biological: Delayed second dose of oral cholera vaccine, Euvichol-Plus
Experimental
interventional 12 months interval between OCV doses
This intervention arm will modify the recommended interval for administration of the second Euvichol-Plus®, which will be extended to 12 months.
Biological: Delayed second dose of oral cholera vaccine, Euvichol-Plus
Active comparator
control arm (standard 14-day interval)
Participants will receive the oral cholera vaccine, Euvichol-Plus®, according to the manufacturer instructions: 2 doses two weeks apart.
Biological: Oral cholera vaccine, Euvichol-Plus, according to manufacturer notice

Interventions

BiologicalDelayed second dose of oral cholera vaccine, Euvichol-Plus
The intervention arms (6 and 12 months) will modify the recommended interval for administration of the second vaccine dose, which will be extended to 6 and 12 months according to the intervention arm.
BiologicalOral cholera vaccine, Euvichol-Plus, according to manufacturer notice
Euvichol-Plus, a WHO prequalified oral cholera vaccine, contains modified killed whole cell vaccine of formalin killed Vibrio cholerae strains of O1 Inaba, O1 Ogawa and O139. In the control arm, participants will receive the Euvichol-Plus following the manufacturer recommendations: two doses administered orally 14 days apart for individuals aged ≥1 year.

What researchers measure

Primary outcomes

Serum vibriocidal antibody specific to V. cholerae O1, Inaba, Ogawa and O139 strains
Serum vibriocidal antibody Geometric Mean Titre (GMT)
Time frame: 14 days after the administration of the second vaccine dose

Secondary outcomes

Serum vibriocidal antibody specific to V. cholerae O1, Inaba, Ogawa and O139 strains
Serum vibriocidal antibody Geometric Mean Titre (GMT)
Time frame: Just before and 14 days after administration of the first dose and and just before the second OCV dose
Serum vibriocidal anti-OSP IgA, IgG, IgM
Serum vibriocidal anti-OSP IgA, IgG, IgM titres measured using Enzyme-linked immunosorbend essay (ELISA)
Time frame: Just before and 14 days after administration of the first and the second OCV dose
Anti-CtxB immunoglobulines
Anti-CtxB immunoglobulines titres measured using Enzyme-linked immunosorbend essay (ELISA)
Time frame: Just before and 14 days after administration of the first and the second OCV dose
Immediate Adverse Events (IAEs) (Safety)
All participants will be observed by clinicians for 30 minutes after each vaccination to monitor for any immediate adverse events (IAEs)
Time frame: Up to 30 minutes after each OCV dose
Adverse events (AEs) (Safety)
Solicited and unsolicited AEs will be actively monitored by clinicians at the study visits for 14 days following administration of each vaccine dose.
Time frame: Until 14 days after the administration of the first and the second OCV dose
Serious Adverse Events (SAEs) (Safety)
SAEs will be monitored by clinicians up to end of the participants' follow-up.
Time frame: Up to end of the participants' follow-up i.e. 18months

Other outcomes

Serum vibriocidal antibody specific to V. cholerae O1, Inaba, Ogawa and O139 strains
Serum vibriocidal antibody Geometric Mean Titre (GMT)
Time frame: In a subgroup of participants: At 4, 7, 28 and 180 days after administration of the first and the second OCV dose
Serum vibriocidal anti-OSP IgA, IgG, IgM
Serum vibriocidal anti-OSP IgA, IgG, IgM titres measured using Enzyme-linked immunosorbend essay (ELISA)
Time frame: In a subgroup of participants: At 4, 7, 28 and 180 days after administration of the first and the second OCV dose
Anti-CtxB immunoglobulines
Anti-CtxB immunoglobulines titres measured using Enzyme-linked immunosorbend essay (ELISA)
Time frame: In a subgroup of participants: At 4, 7, 28 and 180 days after administration of the first and the second OCV dose

Study locations

1 site

Dixinn
Conakry, Guinea

Updates

Tracking since Sep 25, 2026

No changes since tracking began. The registry record was last updated on Mar 7, 2023, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗

Registry details

Key details

Study ID: NCT05453253
Lead sponsor: Epicentre
Collaborators: Ministry of Health, Guinea, Massachusetts General Hospital, Médecins Sans Frontières, Belgium
Responsible party: Sponsor
First posted: Jul 12, 2022
Start date: Jul 20, 2022
Primary completion: Feb 1, 2024 (estimated)
Completion: Jul 1, 2024 (estimated)
Last update: Mar 7, 2023

Oversight

Data monitoring committee: Yes
FDA-regulated drug: No
FDA-regulated device: No

View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is status unknown, as verified in Mar 2023. You cannot join it, but the record below documents what was studied.

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