Figure 1 . Age characteristics of the Nicaraguan Pediatric Influenza Cohort Study (NPICS) from 2011–2016. A) Age of all children enrolled in NPICS from 2011­­–2016, B) Age structure of NPICS cohort for those under 1 year of age, C) Age of new enrollees by year following the initial enrollment period, D) Reported sex and age distribution of all enrollees.