Assessment of vaccine herd protection in a cluster-randomised trial of Vi conjugate vaccine against typhoid fever: results of further analysis.

ABSTRACT:

Background

A cluster-randomised trial of Vi-tetanus toxoid (Vi-TT) conjugate vaccine conducted in urban Bangladeshi children found a high level of direct protection by Vi-TT but no significant vaccine herd protection. We reassessed the trial using a "fried egg" analysis to evaluate whether herd protection might have been obscured by transmission of typhoid into the clusters from the outside.

Methods

A participant- and observer-blind, cluster-randomised trial was conducted between February 14, 2018 and August 12, 2019 in three wards of Mirpur, a densely populated urban area of Dhaka, Bangladesh. Children 9 months to under 16 years of age in 150 geographic clusters, which had a total of 311,289 persons present at baseline or entering during follow-up, were randomised by cluste

SUBMITTER: Khanam F 

PROVIDER: S-EPMC10114505 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature