A Phase 2 interventional study of OSP:rTTHc CCV 25 ㎍ with Aluminum phosphate and OSP:rTTHc CCV 25 ㎍ without Aluminum phosphate in Cholera Vaccination, sponsored by International Vaccine Institute. Recruiting at 1 site in Kenya. Open to participants aged 1 Year to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-04-03.
Sponsored by International Vaccine Institute · Phase 2, Interventional, and Prevention
This phase II study is intended to determine the immunogenicity and safety of single dose and two doses of OSP:rTTHc cholera conjugate vaccine (CCV) with or without alum adjuvant. The study will guide the future dosing schedule and formulation of CCV (with or without Aluminum phosphate adjuvant) expected to be needed in adults and children in cholera-endemic region.
This is phase II, randomized, controlled, safety and immunogenicity study of one and two doses of the of CCV 25 μg (with and without alum) in cholera-endemic region.
A total of 390 eligible participants will be recruited in the study into 3 age cohorts.
This will be a randomized, placebo-controlled, observer blind study in adults aged 18 to 45 years (cohort A) and children aged 5 to 17 years (cohort B) followed by a randomized, active-controlled, partial open label study in children aged 1 to 4 years (cohort C).
The DSMB must review the safety data of each cohort and approve study continuation before investigational product administration of the next younger cohort is initiated (age descending study scheme).
In cohort A, 50 adult participants aged 18 to 45 years will be randomly divided into 5 arms to receive the assigned investigational product as follows:
Arm A1 (n=10): one dose of CCV 25 μg with alum and one dose of placebo at 6 months interval Arm A2 (n=10): one dose of CCV 25 μg without alum and one dose of placebo at 6 months interval Arm A3 (n=10): two doses of CCV 25 μg with alum at 6 months interval Arm A4 (n=10): two doses of CCV 25 μg without alum at 6 months interval Arm A5 (n=10): two doses of placebo at 6 months interval
In cohort B, 90 children aged 5 to 17 years will be randomly divided into 5 arms to receive the assigned investigational product as follows:
Arm B1 (n=20): one dose of CCV 25 μg with alum and one dose of placebo at 6 months interval Arm B2 (n=20): one dose of CCV 25 μg without alum and one dose of placebo at 6 months interval Arm B3 (n=20): two doses of CCV 25 μg with alum at 6 months interval Arm B4 (n=20): two doses of CCV 25 μg without alum at 6 months interval Arm B5 (n=10): two doses of placebo at 6 months interval
In cohort C, 250 children aged 1 to 4 years will be randomly divided into 10 arms to receive the assigned investigational product as follows:
Arm C1 (n=30): one dose of CCV 25 μg with alum and one dose of placebo at 6 months interval Arm C2 (n=30): one dose of CCV 25 μg without alum and one dose of placebo at 6 months interval Arm C3 (n=30): two doses of CCV 25 μg with alum at 6 months interval Arm C4 (n=30): two doses of CCV 25 μg without alum at 6 months interval Arm C5 (n=20): two doses of placebo at 6 months interval Arm C6 (n=30): two doses of Euvichol®-Plus at 2 weeks interval Arm C7 (n=20): one dose of CCV 25 μg with alum and one dose of Euvichol®-Plus at 6 months interval Arm C8 (n=20): one dose of CCV 25 μg without alum and one dose of Euvichol®-Plus at 6 months interval Arm C9 (n=20): one dose of Euvichol®-Plus and one dose of CCV 25 μg with alum at 6 months interval Arm C10 (n=20): one dose of Euvichol®-Plus and one dose of CCV 25 μg without alum at 6 months interval
Route of vaccination: CCV 25 μg (with or without alum) and placebo are administered by intramuscular (IM) injection. Euvichol®-Plus is administered orally.
83 studies on the registry are indexed under Cholera; 16 are open to participants now.
This study's planned enrollment of 390 is above the median of 262 across 72 interventional studies indexed under Cholera.
Browse Cholera studies →International Vaccine Institute is the lead sponsor of 47 studies on the registry; 12 are open to participants now.
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.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
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 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.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
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.
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.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
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.
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.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
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.
0.5 mL per dose; dosing schedule/duration: 1 dose or 2 doses at 168-days interval administered intramuscularly
Biological: OSP:rTTHc CCV 25 ㎍ with Aluminum phosphate
0.5 mL per dose; dosing schedule/duration: 1 dose or 2 doses at 168-days interval administered intramuscularly
Biological: OSP:rTTHc CCV 25 ㎍ without Aluminum phosphate
1.5 mL per dose; dosing schedule/duration: 2 doses at 14-days interval administered orally
Biological: Euvichol®-Plus
0.5 mL per dose; dosing schedule/duration: 2 doses at 168-days interval administered intramuscularly
Other: Placebo
0.5 mL per dose of CCV administered intramuscularly and 1.5 mL dose of Euvichol®-Plus administered orally at 168-days interval
Biological: CCV with Aluminum, Euvichol®-Plus
0.5 mL per dose of CCV administered intramuscularly and 1.5 mL dose of Euvichol®-Plus administered orally at 168-days interval
Biological: CCV without Aluminum, Euvichol®-Plus
OSP:rTTHc Cholera Conjugate with Aluminum phosphate Cohort Arms A1, A3, B1, B3, C1, C3, C10
OSP:rTTHc Cholera Conjugate without Aluminum phosphate Cohort Arms A2, A4, B2, B4, C2, C4
V. cholerae O1 and O139 bivalent inactivated oral cholera vaccine cohort Arm C6
Sterile 0.9% sodium chloride cohort Arms A5, B5, C5
1. OSP:rTTHc CCV 25 # with Aluminum phosphate OSP:rTTHc Cholera Conjugate with Aluminum phosphate 2. Euvichol®-Plus V. cholerae O1 and O139 bivalent inactivated oral cholera vaccine Cohort Arms C7, C9
1. OSP:rTTHc CCV 25 # without Aluminum phosphate OSP:rTTHc Cholera Conjugate without Aluminum phosphate 2. Euvichol®-Plus V. cholerae O1 and O139 bivalent inactivated oral cholera vaccine Cohort Arms C8, C10
Seroconversion of Serum vibriocidal antibody titers responses to V. cholerae O1 Inaba and O1 Ogawa at 28 days after one dose vaccination of CCV 25 μg (with or without alum) in adults (aged 18 to 45 years) and in children (aged 1 to 17 years).
\- Proportion of participants achieving seroconversion (defined as at least 4-fold increase from baseline) of serum vibriocidal antibody titers at 28 days after one dose vaccination of CCV (with or without alum) 25 μg / placebo
Time frame: Baseline and at 28 days post the first dose of either CCV with alum, CCV without alum or placebo
GMT of Serum vibriocidal antibody titers to V. cholerae O1 Inaba and O1 Ogawa after one dose of CCV 25 μg (with or without alum) in adults (aged 18 to 45 years) and in children (aged 1 to 17 years)
\- GMT of serum vibriocidal antibody titers at 28 days after one dose vaccination of CCV (with or without alum) 25 μg / placebo
Time frame: Baseline and at 28 days post the first dose of either CCV with alum, CCV without alum or placebo
Seroconversion of vibriocidal titers against V. cholerae O1 Inaba and O1 Ogawa after two doses of Euvichol®-Plus in children aged 1 to 4 years
Proportion of participants achieving seroconversion of serum vibriocidal antibody titers at 14 days after two doses of Euvichol®-Plus
Time frame: Baseline and at 14 days post two doses of Euvichol®-Plus
GMT of vibriocidal titers against V. cholerae O1 Inaba and O1 Ogawa after two doses of Euvichol®-Plus in children aged 1 to 4 years
GMT of serum vibriocidal antibody titers at 14 days after two doses of Euvichol®-Plus compared to baseline
Time frame: Baseline and at 14 days after two doses of Euvichol®-Plus
Seroconversion of Serum OSP IgG antibody titers against V. cholerae O1 Inaba after one dose vaccination of CCV 25 μg (with or without alum) in adults (aged 18 to 45 years) and in children (aged 1 to 17 years).
Proportion of participants achieving seroconversion (defined as at least 4-fold increase from baseline) of serum OSP IgG antibody titers at 28 days after one dose vaccination of CCV (with or without alum) 25 μg / placebo
Time frame: Baseline and at 28 days post the first dose of either CCV with alum, CCV without alum or placebo
GMT of Serum OSP IgG antibody titers to V. cholerae O1 Inaba and O1 Ogawa after one dose of CCV 25 μg (with or without alum) in adults (aged 18 to 45 years) and in children (aged 1 to 17 years)
\- GMT of serum OSP IgG antibody titers at 28 days after one dose vaccination of CCV (with or without alum) 25 μg / placebo
Time frame: Baseline and at 28 days post the first dose of either CCV with alum, CCV without alum or placebo
Seroconversion of OSP IgG titers against V. cholerae O1 Inaba and O1 Ogawa after two doses of Euvichol®-Plus in children aged 1 to 4 years
Proportion of participants achieving seroconversion of serum OSP IgG antibody titers at 14 days after two doses of Euvichol®-Plus
Time frame: Baseline and at 14 days post two doses of Euvichol®-Plus
GMT of OSP IgG titers against V. cholerae O1 Inaba and O1 Ogawa after two doses of Euvichol®-Plus in children aged 1 to 4 years:
GMT of serum OSP IgG antibody titers at 14 days after two doses of Euvichol®-Plus compared to baseline
Time frame: Baseline and at 14 days after two doses of Euvichol®-Plus
Serious adverse events (SAEs) and adverse events of special interest (AESIs) and medically attended adverse event (MAAE)
Occurrence of any SAE / AESI / MAAE from the first dose vaccination throughout the final study visit
Time frame: through study completion, an average of 6 months
Immediate adverse events
Occurrence of immediate adverse events within 30 minutes after each dose vaccination
Time frame: Within 30 minutes post each dose
Solicited adverse events
Occurrence of solicited injection site and solicited systemic adverse events from the time of each study vaccination through 7 days after each study vaccination
Time frame: Within 7 days post each dose
Unsolicited adverse events
Occurrence of unsolicited adverse events from the time of each study vaccination through 28 days after each study vaccination.
Time frame: Within 28 days post each dose
Seroconversion of Serum vibriocidal antibody titers responses to V. cholerae O1 Inaba and O1 Ogawa at 28 days after two doses of CCV 25 μg (with or without alum) / placebo in adults (aged 18 to 45 years) and in children (aged 1 to 17 years.
\- Proportion of participants achieving seroconversion of serum vibriocidal antibody titers at 28 days after two doses of CCV 25 μg (with or without alum) / placebo
Time frame: Baseline and at 28 days post the second dose of either CCV with alum, CCV without alum or placebo
Seroconversion of IgG antibody responses to OSP against V. cholerae O1 Inaba at 28 days after two doses of CCV 25 μg (with or without alum).or placebo in adults (aged 18 to 45 years) and in children (aged 1 to 17 years.
\- Proportion of participants achieving seroconversion of serum anti-OSP IgG antibody titer at 28 days after two doses of CCV (with or without alum) 25 μg or placebo
Time frame: Baseline and at 28 days post the second dose of either CCV with alum, CCV without alum or placebo]
Seroconversion of Serum vibriocidal antibody titers against V. cholerae O1 Inaba and O1 Ogawa at 28 days after booster dose in heterologous boosting group of CCV with or without alum 25 μg and Euvichol®-Plus in children aged 1 to 4 years
\- Proportion of participants achieving seroconversion of serum vibriocidal antibody titers after the heterologous booster dose
Time frame: Baseline and at 28 days post the heterologous booster dose
Seroconversion of IgG antibody responses to OSP against V. cholerae O1 Inaba at 28 days after booster dose in heterologous boosting group of CCV with or without alum 25 μg and Euvichol®-Plus in children aged 1 to 4 years
\- Proportion of participants achieving seroconversion of serum vibriocidal antibody titers after the heterologous booster dose
Time frame: Baseline and at 28 days post the heterologous booster dose
GMT of Serum vibriocidal antibody titers responses to V. cholerae O1 Inaba and O1 Ogawa at 28 days after two doses of CCV 25 μg (with or without alum) / placebo in adults (aged 18 to 45 years) and in children (aged 1 to 17 years.
GMT of serum vibriocidal antibody titers at 28 days after two doses of CCV 25 μg (with or without alum) / placebo
Time frame: Baseline and at 28 days post the second dose of either CCV with alum, CCV without alum or placebo
GMT of IgG antibody responses to OSP against V. cholerae O1 Inaba at 28 days after two doses of CCV 25 μg (with or without alum).or placebo in adults (aged 18 to 45 years) and in children (aged 1 to 17 years.
GMT of serum anti-OSP IgG antibody titer at 28 days after two doses of CCV (with or without alum) 25 μg or placebo
Time frame: Baseline and at 28 days post the second dose of either CCV with alum, CCV without alum or placebo]
GMT of Serum vibriocidal antibody titers against V. cholerae O1 Inaba and O1 Ogawa at 28 days after booster dose in heterologous boosting group of CCV with or without alum 25 μg and Euvichol®-Plus in children aged 1 to 4 years
GMT of serum vibriocidal antibody titers after the heterologous booster dose
Time frame: Baseline and at 28 days post the heterologous booster dose
GMT of IgG antibody responses to OSP against V. cholerae O1 Inaba at 28 days after booster dose in heterologous boosting group of CCV with or without alum 25 μg and Euvichol®-Plus in children aged 1 to 4 years
GMT of serum vibriocidal antibody titers after the heterologous booster dose
Time frame: Baseline and at 28 days post the heterologous booster dose
Plan to share: No
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Started Jan 2026 (actual). Primary completion is estimated for Mar 2027, 14 months after the start.
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