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. 2021 Mar 19;9(3):281.
doi: 10.3390/vaccines9030281.

Evaluation of Typhoid Conjugate Vaccine Effectiveness in Ghana (TyVEGHA) Using a Cluster-Randomized Controlled Phase IV Trial: Trial Design and Population Baseline Characteristics

Affiliations

Evaluation of Typhoid Conjugate Vaccine Effectiveness in Ghana (TyVEGHA) Using a Cluster-Randomized Controlled Phase IV Trial: Trial Design and Population Baseline Characteristics

Andrea Haekyung Haselbeck et al. Vaccines (Basel). .

Abstract

Typhoid fever remains a significant health problem in sub-Saharan Africa, with incidence rates of >100 cases per 100,000 person-years of observation. Despite the prequalification of safe and effective typhoid conjugate vaccines (TCV), some uncertainties remain around future demand. Real-life effectiveness data, which inform public health programs on the impact of TCVs in reducing typhoid-related mortality and morbidity, from an African setting may help encourage the introduction of TCVs in high-burden settings. Here, we describe a cluster-randomized trial to investigate population-level protection of TYPBAR-TCV®, a Vi-polysaccharide conjugated to a tetanus-toxoid protein carrier (Vi-TT) against blood-culture-confirmed typhoid fever, and the synthesis of health economic evidence to inform policy decisions. A total of 80 geographically distinct clusters are delineated within the Agogo district of the Asante Akim region in Ghana. Clusters are randomized to the intervention arm receiving Vi-TT or a control arm receiving the meningococcal A conjugate vaccine. The primary study endpoint is the total protection of Vi-TT against blood-culture-confirmed typhoid fever. Total, direct, and indirect protection are measured as secondary outcomes. Blood-culture-based enhanced surveillance enables the estimation of incidence rates in the intervention and control clusters. Evaluation of the real-world impact of TCVs and evidence synthesis improve the uptake of prequalified/licensed safe and effective typhoid vaccines in public health programs of high burden settings. This trial is registered at the Pan African Clinical Trial Registry, accessible at Pan African Clinical Trials Registry (ID: PACTR202011804563392).

Keywords: Ghana; cluster randomized trial; typhoid conjugate vaccine; typhoid fever.

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Conflict of interest statement

The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.

Figures

Figure 1
Figure 1
TyVEGHA catchment area. Figure (a) depicts the TyVEGHA catchment area located in Asante Akim North in Ghana; Figure (b) illustrates the demarcation of the TyVEGHA enumeration areas.
Figure 2
Figure 2
Trial flowchart.
Figure 3
Figure 3
Community-based referral system during SETA Plus surveillance period. Notes. HCF, health care facility; SOP, Standard Operating Procedures.

References

    1. GBD 2017 Typhoid and Paratyphoid Collaborators, The global burden of typhoid and paratyphoid fevers: A systematic analysis for the Global Burden of Disease Study 2017. Lancet Infect. Dis. 2019;19:369–381. doi: 10.1016/S1473-3099(18)30685-6. - DOI - PMC - PubMed
    1. John J., Van Aart C.J.C., Grassly N.C. The Burden of Typhoid and Paratyphoid in India: Systematic Review and Meta-analysis. PLoS Negl. Trop. Dis. 2016;10:e0004616. doi: 10.1371/journal.pntd.0004616. - DOI - PMC - PubMed
    1. Buckle G.C., Walker C.L., Black R.E. Typhoid fever and paratyphoid fever: Systematic review to estimate global morbidity and mortality for 2010. J. Glob. Health. 2012;2:010401. doi: 10.7189/jogh.01.010401. - DOI - PMC - PubMed
    1. Crump J.A., Luby S.P., Mintz E.D. The global burden of typhoid fever. Bull. World Health Organ. 2004;82:346–353. - PMC - PubMed
    1. Mogasale V., Maskery B., Ochiai R.L., Lee J.S., Mogasale V.V., Ramani E., Kim Y.K., Wierzba T.F. Burden of typhoid fever in low-income and middle-income countries: A systematic, literature-based update with risk-factor adjustment. Lancet Glob. Health. 2014;2:e570–e580. doi: 10.1016/S2214-109X(14)70301-8. - DOI - PubMed

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