CompletedPhase 2

Immunogenicity and Tolerability of Booster Typhoid Conjugate Vaccine (TCV) 5-6 Years After Initial Dose in Children in Burkina Faso

Burkina Faso147 participantsStarted 2024-08-17

Plain-language summary

This study evaluated the persistence of immunity following primary typhoid conjugate vaccination in early childhood and assessed the immunogenicity and safety of a booster dose administered 5-6 years later. Children previously enrolled in a Phase 2 randomized clinical trial of Vi-tetanus toxoid conjugate vaccine (Vi-TT) were re-enrolled at 6-7 years of age. Participants who previously received Vi-TT received a booster dose of Vi-CRM, while control participants received their first TCV dose. Anti-Vi IgG antibody responses were measured at baseline and 28 days post-vaccination. Safety was assessed through solicited and unsolicited adverse events. This study provides data on durability of TCV immunity and the potential role of booster dosing in endemic settings.

Who can participate

Age range

6 Years – 7 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Male or female children previously enrolled in the 2018-2019 Phase 2 typhoid conjugate vaccine trial * Residence within study area * Parent/guardian provides informed consent Exclusion Criteria: * Receipt of blood products within 6 months * Prior typhoid conjugate vaccine receipt outside the study * Medical condition interfering with evaluation * Acute illness or fever prior to vaccination (temporary exclusion)

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Anti-Vi IgG Antibody Response (Immunogenicity)

Timeframe: Baseline (Day 0) and Day 28 post-vaccination

Trial details

NCT IDNCT07624175

SponsorKathleen Neuzil

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2024-10-26

View on ClinicalTrials.gov More Typhoid trials