Age-descending safety and immune response of a cholera conjugate vaccine in people aged 1–45

A Phase II, Randomized, Controlled, Age-descending Study in Adults and Children to Evaluate the Safety and Immunogenicity of the OSP:rTTHc Cholera Conjugate Vaccine in Cholera-endemic Region

This trial will test whether one or two doses of a 25 μg cholera conjugate vaccine, with or without an aluminum adjuvant, are safe and produce immune responses in people aged 1 to 45 living in a cholera-endemic area.

Quick facts

• Phase: Phase 2
• Study type: Interventional
• Enrollment: 390 (estimated)
• Ages: 1 Year to 45 Years
• Sex: All
• Sponsor: International Vaccine Institute (Academic / other)
• Drugs / interventions: chemotherapy, radiation, prednisone
• Locations: 1 site (Nairobi, Kenyatta National Hospital Complex)
• Trial ID: NCT07509047 on ClinicalTrials.gov

What this trial studies

This is a randomized, controlled, phase II safety and immunogenicity trial enrolling about 390 participants across three age cohorts (18–45, 5–17, and 1–4 years) using an age-descending design. Adults and older children will be enrolled in observer-blind, placebo-controlled arms comparing single versus two 25 μg doses of OSP:rTTHc CCV with or without aluminum phosphate; the youngest cohort will be randomized with active control and partial open-label elements. Doses are given six months apart where two-dose schedules are used, and an independent DSMB must clear safety before enrolling the next younger cohort. The trial includes comparator arms with licensed oral cholera vaccine (Euvichol®-Plus) and placebo to guide optimal formulation and dosing for endemic settings.

Who should consider this trial

Good fit: Healthy individuals aged 1 to 45 who live in the study area, can comply with visits, and can provide informed consent (or have a legal guardian provide consent) are ideal candidates.

Not a fit: People with known allergy to vaccine components, major congenital abnormalities, known immunodeficiency (including HIV), or recent immunosuppressive therapy are excluded and unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, the study could identify a safe and effective dosing schedule and formulation of the cholera conjugate vaccine that improves protection for children and adults in endemic areas.

How similar studies have performed: Early-phase work on OSP-conjugate cholera vaccines and other conjugate approaches has shown promising immune responses, but larger trials in endemic populations are still limited.

Eligibility criteria

Inclusion Criteria:

1. Individuals aged 1 to 45 years at consent
2. Participants/ Participants' legally authorized representative (LAR) willing to provide written informed consent to participate in the study voluntarily
3. Participants who can comply with the study requirements
4. Individuals in good health as determined by the outcome of medical history, physical examination, and the clinical judgment of the investigator

Exclusion Criteria:

1. Known history or allergy to investigational vaccine components or other medications, or any other allergies
2. Individuals with major congenital abnormalities
3. Known history of immune function disorders including immunodeficiency diseases (known HIV infection¥ or other immune function disorders)
4. Use of systemic steroids within past 6 months (\>10 mg/day prednisone equivalent for periods exceeding 2 consecutive weeks), or receive chemotherapy, radiation therapy or other immunosuppressive drugs within the past 6 months.
5. Any abnormality or chronic disease which in the opinion of the investigator might be detrimental for the safety of the participant and interfere with the assessment of the study objectives
6. Individuals with behavioral or cognitive impairment or psychiatric disease or neural disorders that, in the opinion of the investigator, could interfere with the participant's ability to participate in the trial
7. Individuals with splenectomy
8. Individuals with known bleeding disorders
9. Receipt of blood, blood-derived products, or immunoglobulin products in the past 3 months
10. Individuals who have received other vaccines from 4 weeks prior to the first dose of test vaccination or planned to receive any vaccine within 4 weeks of the last dose of the investigational product.
11. Individuals with active or known previous Vibrio cholerae infection
12. Individuals with a history of severe diarrhea in the last 6 months requiring care at a medical facility lasting 24 hours or more
13. Individuals with prior receipt of a cholera vaccine in the last 5 years
14. Any female participant who is lactating or pregnant
15. Females of childbearing potential who do not agree to use an effective birth control method for at least 4 weeks before the screening and up to 12 weeks after the study vaccination.
16. Individuals enrolled in another clinical trial within 6 months prior to enrollment, concomitantly enrolled or scheduled to be enrolled in another trial during study period
17. Individuals who are research staff involved with the clinical trial or family/household members of research staff
18. As per Investigator's medical judgement, an individual could also be excluded from the study despite meeting all inclusion/exclusion criteria mentioned above
19. Children below 5 years old with Weight for Height Z score and/or Height for Age Z score of less than -2

Where this trial is running

Nairobi, Kenyatta National Hospital Complex

• KAVI-Institute of Clinical Research, University — Nairobi, Kenyatta National Hospital Complex, Kenya (Recruiting)

Study contacts

• Principal investigator: Julia Lynch, MD — International Vaccine Institute
• Study coordinator: Naveena D'Cor, MD

Conditions Cholera Vaccination; Cholera Conjugate Vaccine; O Specific Polysaccharide; Recombinant Tetanus Toxoid Heavy Chain Fragment; Cholera Vaccine