AbstractBackgroundWhile live attenuated monovalent human rotavirus vaccine (Rotarix) efficacy has been characterized through randomized studies, its effectiveness, especially in non-clinical settings, is unclear. In this study, we estimate direct, indirect, and overall effectiveness of Rotarix vaccination.MethodsWe analyze 29 months of all-cause diarrhea surveillance from a child cohort (n=376) and ten years of serial population-based case-control lab-confirmed rotavirus data (n=2489) from rural Ecuador during which Rotarix vaccination was introduced. We estimate: 1) the direct effect of vaccination from a cohort of children born from 2008-2013 using Cox regression to compare time to first all-cause diarrhea case by vaccine status; and 2) the overall effect on all-cause diarrheal and symptomatic and asymptomatic rotavirus infection for all age groups, including indirect effects on adults, from the case-control data using weighted logistic regression.ResultsRotarix vaccination provided direct protection against all-cause diarrhea among children 0.5 - 2 years (All-cause diarrhea reduction for receipt of 2 doses of Rotarix=57.1%, 95% CI: 16.6, 77.9%). Overall effectiveness against rotavirus infection was strong (Exposure to 100% coverage of Rotarix vaccination was associated with an 85.5% reduction, 95% CI: 61.1-94.6%) compared to 0% coverage. Indirect effects were observed among older, vaccine-ineligible children and adults (84.5% reduction, 95% CI: 48.2-95.4%). Vaccine effectiveness was high against both symptomatic (48.3% reduction,95% CI: 0.03-73.1%) and asymptomatic infection (90.1% reduction, 95% CI: 56.9-97.7%).ConclusionsRotarix vaccination suppresses overall transmission. It is highly effective among children in a rural community setting and provides population-level benefits through indirect protection among adults.
Indirect Effects of the COVID-19 Pandemic on Childhood Infection in England: A Population Based Observational Study
