Anderson ML, et al. - This study was undertaken to investigate the effectiveness of the influenza vaccine in reducing hospitalizations and mortality among elderly persons by applying an observational research design that reduces the possibility of bias and confounding. Researchers utilized a regression discontinuity design to the sharp change in vaccination rate at age 65 years that resulted from an age-based vaccination policy in the United Kingdom. Researchers included adults aged 55 to 75 years residing in the study area from 2000 to 2014 in England and Wales. In this study, 170 million episodes of care and 7.6 million deaths were included. In this population, current vaccination approaches prioritizing elderly persons may be less efficient than believed at reducing serious morbidity and mortality, which suggests that supplementary strategies may be necessary.