 The goal of this randomized clinical trial is to determine whether immunizing children in Hutterite colonies with inactivated influenza vaccine can prevent influenza and its complications in other colony members. Furthermore, the study will assess the indirect benefit to Hutterites at high risk of complications. The study is a blinded, cluster randomized controlled trial among Hutterite colonies to test the hypothesis that high immunization rates 70 of healthy children with inactivated influenza vaccine reduces transmission of influenza to other colony members. Randomization of these homogeneous, moderately sized colonies where there is regular spread facilitated by a communal lifestyle, but limited re-introduction because of relative isolation from outside community, represents a unique opportunity to test the hypothesis of indirect benefit under close to ideal conditions. The primary outcome will be laboratory-confirmed influenza. Secondary outcomes include influenza-like illness, otitis media, physician visits, antimicrobial prescriptions, absenteeism, lower respiratory tract infection, hospitalizations, and death. 