Safety and Efficacy of a Typhoid Conjugate Vaccine in Malawian Children



Patel, Priyanka D, Patel, Pratiksha, Liang, Yuanyuan, Meiring, James E, Misiri, Theresa, Mwakiseghile, Felistas, Tracy, J Kathleen, Masesa, Clemens, Msuku, Harrison, Banda, David
et al (show 16 more authors) (2021) Safety and Efficacy of a Typhoid Conjugate Vaccine in Malawian Children. NEW ENGLAND JOURNAL OF MEDICINE, 385 (12). pp. 1104-1115.

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Abstract

<h4>Background</h4>Typhoid fever caused by multidrug-resistant H58 <i>Salmonella</i> Typhi is an increasing public health threat in sub-Saharan Africa.<h4>Methods</h4>We conducted a phase 3, double-blind trial in Blantyre, Malawi, to assess the efficacy of Vi polysaccharide typhoid conjugate vaccine (Vi-TCV). We randomly assigned children who were between 9 months and 12 years of age, in a 1:1 ratio, to receive a single dose of Vi-TCV or meningococcal capsular group A conjugate (MenA) vaccine. The primary outcome was typhoid fever confirmed by blood culture. We report vaccine efficacy and safety outcomes after 18 to 24 months of follow-up.<h4>Results</h4>The intention-to-treat analysis included 28,130 children, of whom 14,069 were assigned to receive Vi-TCV and 14,061 were assigned to receive the MenA vaccine. Blood culture-confirmed typhoid fever occurred in 12 children in the Vi-TCV group (46.9 cases per 100,000 person-years) and in 62 children in the MenA group (243.2 cases per 100,000 person-years). Overall, the efficacy of Vi-TCV was 80.7% (95% confidence interval [CI], 64.2 to 89.6) in the intention-to-treat analysis and 83.7% (95% CI, 68.1 to 91.6) in the per-protocol analysis. In total, 130 serious adverse events occurred in the first 6 months after vaccination (52 in the Vi-TCV group and 78 in the MenA group), including 6 deaths (all in the MenA group). No serious adverse events were considered by the investigators to be related to vaccination.<h4>Conclusions</h4>Among Malawian children 9 months to 12 years of age, administration of Vi-TCV resulted in a lower incidence of blood culture-confirmed typhoid fever than the MenA vaccine. (Funded by the Bill and Melinda Gates Foundation; ClinicalTrials.gov number, NCT03299426.).

Item Type: Article
Uncontrolled Keywords: TyVAC Malawi Team, Humans, Salmonella typhi, Typhoid Fever, Polysaccharides, Bacterial, Meningococcal Vaccines, Typhoid-Paratyphoid Vaccines, Vaccines, Conjugate, Incidence, Follow-Up Studies, Double-Blind Method, Child, Child, Preschool, Infant, Malawi, Female, Male, Intention to Treat Analysis
Divisions: Faculty of Health and Life Sciences
Faculty of Health and Life Sciences > Institute of Infection, Veterinary and Ecological Sciences
Depositing User: Symplectic Admin
Date Deposited: 12 May 2022 10:10
Last Modified: 15 Mar 2024 05:16
DOI: 10.1056/NEJMoa2035916
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3154662