Abstract
Few data exist regarding the healthcare and societal burden of culture-confirmed influenza illness in European and Israeli children. The current analysis describes this burden in vaccinated and unvaccinated children 2-17 years of age. Healthcare and societal burden outcomes were prospectively collected for culture-confirmed influenza illness in three previous randomized studies: a study of live attenuated influenza vaccine (LAIV) versus placebo in children aged <48 months attending day care (N = 846-973), and studies of LAIV versus inactivated influenza vaccine (IIV) in children aged <72 months with recurrent respiratory infections (N = 1,609) and in children aged 6-17 years with asthma (N = 2,211). The incidence of each endpoint among enrolled subjects and subjects with influenza was determined by treatment group and by country. Among subjects with influenza, 57-91% missed school or day care, 45-90% used non-antibiotic medications, 29-55% of parents missed work, 17-55% used antibiotics, 11-62% had additional provider visits, and 9-20% had acute otitis media. Where evaluated, rates of outcomes were generally similar between countries. Among all children enrolled, LAIV recipients missed 324-902 and 150 fewer days of day care per 1,000 children than those of placebo and IIV recipients, respectively; parents of LAIV recipients missed 197-340 and 76 fewer days of work per 1,000 children than those of placebo and IIV recipients, respectively. Influenza illness in European and Israeli children 2-17 years of age resulted in a considerable absenteeism and healthcare utilization that was similar across the countries studied. These data underscore the potential benefits of annual vaccination of children against influenza.