Baker JM, et al. - From the MarketScan Research Databases, time series data on rates of hospitalization for rotavirus gastroenteritis (RVGE) and all-cause acute gastroenteritis (AGE) in the US were analyzed for July 2001-June 2016 to determine the population-level efficacy of infant rotavirus vaccination implemented in 2006 in the US. They analyzed a total of 9,211 RVGE and 726,528 AGE hospitalizations and found vaccine benefits were seen in unvaccinated individuals in all age groups. This indicates the significance of infants as drivers of disease transmission across the population. Bias in observed direct vaccine effectiveness (VE) could be due to imperfect disease classification and changing disease incidence.