Clinical trial NCT03719066: Extended Dose Intervals With Oral Cholera Vaccine in Cameroon
Official title: Effect of Extended Dose Intervals on the Immune Response to Oral Cholera Vaccine in Cameroon
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE2
Conditions: Adverse Reaction to Cholera Vaccine
Cholera Vaccination Reaction
Keywords: cholera
oral cholera vaccine
vibriocidal titer
ELISA antibodies
Adverse event following immunization
Lead sponsor: Johns Hopkins Bloomberg School of Public Health
Sponsor class: OTHER
Collaborators: name: Bill and Melinda Gates Foundation
name: Meilleur Accès aux Soins de Santé (M.A. Santé)
First posted: 2018-10-25
Enrollment: 181
Sex: ALL
Minimum age (years): 1
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Subjects will be randomized to receive two doses of Shanchol oral cholera vaccine with dose intervals of either 2 weeks, 6 months or 11 months.
Primary purpose: PREVENTION

Brief summary: The primary aim of this project is to determine changes in the vibriocidal geometric mean titers (GMT) in subjects who receive the second dose of oral cholera vaccine (OCV) at different intervals: 2 weeks, 6 months, or 11 months following the first dose of vaccine. Secondary aims include a) vibriocidal antibody response rates in subjects who receive OCV at 2 weeks, 6 months, or 11 months following the first dose of vaccine, b) age specific serum vibriocidal GMTs following the second dose among participants given the second dose of OCV at intervals of 2 weeks, 6 months, or 11 months following the first dose of vaccine, c) GMT and antibody response rates of Immunoglobulin A (IgA) and Immunoglobulin G (IgG) anti-lipopolysaccharide (LPS) as measured by ELISA following the second dose among participants given the second dose of OCV at intervals of 2 weeks, 6 months, or 11 months following the first dose of vaccine. The hypothesis is that the vibriocidal GMT following the second dose, when given after 6 or 12 months will not be inferior to the response when the second dose is given according to the standard interval of two weeks.

Detailed description: This is an open label, randomized, phase 2 clinical trial of the immunogenicity of killed oral cholera vaccine (OCV) when the vaccine is administered to participants of three age cohorts (1-4 years, 5-14 years, and \>14 years) and in three dose interval groups (DIGs). The subjects in each age cohort will be randomized to a DIG of 2 weeks (DIG-1), 6 months (DIG-2) or 11 months (DIG-3). A total of 180 subjects from Douala, Cameroon will be enrolled and these are equally divided between the different groups (20 per age/dose interval group). The OCV to be used in the trial is Shanchol.

Blood samples will be collected before the first dose and at intervals following the first dose depending on the dosing interval group assigned. The serum (or plasma) will be tested for antibodies to cholera.

Eligibility criteria: Inclusion Criteria:

1. Age ≥1 year, stratified into different age groups
2. Living in the Soboum Health Area or adjoining area
3. Good health condition, without clinically significant medical history (by participant or guardian, in case of minor)
4. Not pregnant for female subjects.
5. Available to participate for the study duration, including all planned follow-up visits for up to 18 months from screening.
6. Signed informed consent -

Exclusion Criteria:

1. Presence of a significant medical or psychiatric condition (Examples include: Diagnosis and treatment of tuberculosis (TB) or HIV; renal insufficiency; hepatic disease; oral or parenteral medication known to affect the immune function , such as corticosteroids, other immunosuppressant drugs; or behavioural or memory issues)
2. Ever having received oral cholera vaccine.
3. Receipt of an investigational product (within 30 days before vaccination).
4. History of diarrhoea in 7 days prior to first dose of vaccine (defined as ≥3 unformed loose stools in 24 hours).
5. History of chronic diarrhea (lasting for more than 2 weeks in the past 6 months)
6. Current use of laxatives, antacids, or other agents to lower stomach acidity?
7. Planning to become pregnant in the next 2 years

Primary outcomes:
measure: Vibriocidal titer
timeFrame: two weeks after the second dose
Secondary outcomes:
measure: ELISA titres
timeFrame: two weeks after the second dose
Other outcomes:
Locations:
city: Douala
country: Cameroon
facility: M.A. Sante
Study officials:
affiliation: Johns Hopkins Bloomberg School of Public Health
name: David Sack, MD
role: PRINCIPAL_INVESTIGATOR
References: