Typhoid Vaccine Acceleration Consortium Malawi: A Phase III, Randomized, Double-blind, Controlled Trial of the Clinical Efficacy of Typhoid Conjugate Vaccine Among Children in Blantyre, Malawi



Meiring, James E ORCID: 0000-0001-9183-5174, Laurens, Matthew B, Patel, Pratiksha, Patel, Priyanka, Misiri, Theresa, Simiyu, Kenneth, Mwakiseghile, Felistas, Tracy, J Kathleen, Masesa, Clemens, Liang, Yuanyuan
et al (show 7 more authors) (2019) Typhoid Vaccine Acceleration Consortium Malawi: A Phase III, Randomized, Double-blind, Controlled Trial of the Clinical Efficacy of Typhoid Conjugate Vaccine Among Children in Blantyre, Malawi. CLINICAL INFECTIOUS DISEASES, 68 (Suppl ). S50-S58. ISSN 1058-4838, 1537-6591

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Abstract

<h4>Background</h4>Typhoid fever is an acute infection characterized by prolonged fever following the ingestion and subsequent invasion of Salmonella enterica serovar Typhi (S. Typhi), a human-restricted pathogen. The incidence of typhoid fever has been most reported in children 5-15 years of age, but is increasingly recognized in children younger than 5 years old. There has been a recent expansion of multidrug-resistant typhoid fever globally. Prior typhoid vaccines were not suitable for use in the youngest children in countries with a high burden of disease. This study aims to determine the efficacy of a typhoid conjugate vaccine (TCV) that was recently prequalified by the World Health Organization, by testing it in children 9 months through 12 years of age in Blantyre, Malawi.<h4>Methods</h4>In this Phase III, individually randomized, controlled, double-blind trial of the clinical efficacy of TCV, 28 000 children 9 months through 12 years of age will be enrolled and randomized in a 1:1 ratio to receive either Vi-TCV or a meningococcal serogroup A conjugate vaccine. A subset of 600 of these children will be further enrolled in an immunogenicity and reactogenicity sub-study to evaluate the safety profile and immune response elicited by Vi-TCV. Recruiting began in February 2018.<h4>Results</h4>All children will be under passive surveillance for at least 2 years to determine the primary outcome, which is blood culture-confirmed S. Typhi illness. Children enrolled in the immunogenicity and reactogenicity sub-study will have blood drawn before vaccination and at 2 timepoints after vaccination to measure their immune response to vaccination. They will also be followed actively for adverse events and serious adverse events.<h4>Conclusions</h4>The introduction of a single-dose, efficacious typhoid vaccine into countries with high burden of disease or significant antimicrobial resistance could have a dramatic impact, protecting children from infection and reducing antimicrobial usage and associated health inequity in the world's poorest places. This trial, the first of a TCV in Africa, seeks to demonstrate the impact and programmatic use of TCVs within an endemic setting.<h4>Clinical trials registration</h4>NCT03299426.

Item Type: Article
Uncontrolled Keywords: typhoid conjugate vaccine, Malawi, Africa, children, pediatric, TyVAC
Depositing User: Symplectic Admin
Date Deposited: 24 May 2019 13:32
Last Modified: 07 Dec 2024 06:44
DOI: 10.1093/cid/ciy1103
Open Access URL: https://doi.org/10.1093/cid/ciy1103
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URI: https://livrepository.liverpool.ac.uk/id/eprint/3042797