Effect of early life antibiotic use on serologic responses to oral rotavirus vaccine in the MAL-ED birth cohort study

Host microbiome-pathogen interactions in pediatric infections

PURPOSE OF REVIEW

In this review, we discuss recent research that has furthered our understanding of microbiome development during childhood, the role of the microbiome in infections during this life stage, and emerging opportunities for microbiome-based therapies for infection prevention or treatment in children.

RECENT FINDINGS

The microbiome is highly dynamic during childhood and shaped by a variety of host and environmental factors. In turn, the microbiome influences risk and severity of a broad range of infections during childhood, with recent studies highlighting potential roles in respiratory, gastrointestinal, and systemic infections. The microbiome exerts this influence through both direct interactions with potential pathogens and indirectly through modulation of host immune responses. The elucidation of some of these mechanisms by recent studies and the development of effective microbiome-based therapies for adults with recurrent Clostridioides difficile infection highlight the enormous promise that targeting the microbiome has for reducing the burden of infectious diseases during childhood.

SUMMARY

The microbiome has emerged as a key modifier of infection susceptibility and severity among children. Further research is needed to define the roles of microbes other than bacteria and to elucidate the mechanisms underlying microbiome-host and microbiome-pathogen interactions of importance to infectious diseases in children.

Transporting monovalent rotavirus vaccine efficacy estimates to an external target population: a secondary analysis of data from a randomised controlled trial in Malawi

Oral rotavirus vaccine efficacy estimates from randomised controlled trials are highly variable across settings. Although the randomised study design increases the likelihood of internal validity of findings, results from trials may not always apply outside the context of the study due to differences between trial participants and the target population. Here, we used a weight-based method to transport results from a monovalent rotavirus vaccine clinical trial conducted in Malawi between 2005 and 2008 to a target population of all trial-eligible children in Malawi, represented by data from the 2015-2016 Malawi Demographic and Health Survey (DHS). We reweighted trial participants to reflect the population characteristics described by the Malawi DHS. Vaccine efficacy was estimated for 1008 trial participants after applying these weights such that they represented trial-eligible children in Malawi. We also conducted subgroup analyses to examine the heterogeneous treatment effects by stunting and tuberculosis vaccination status at enrolment. In the original trial, the estimates of one-year vaccine efficacy against severe rotavirus gastroenteritis and any-severity rotavirus gastroenteritis in Malawi were 49.2% (95% CI 15.6%-70.3%) and 32.1% (95% CI 2.5%-53.1%), respectively. After weighting trial participants to represent all trial-eligible children in Malawi, vaccine efficacy increased to 62.2% (95% CI 35.5%-79.0%) against severe rotavirus gastroenteritis and 38.9% (95% CI 11.4%-58.5%) against any-severity rotavirus gastroenteritis. Rotavirus vaccine efficacy may differ between trial participants and target populations when these two populations differ. Differences in tuberculosis vaccination status between the trial sample and DHS population contributed to varying trial and target population vaccine efficacy estimates.