setting, clinic visits for influenza were estimated to be 50 to 95 per 1,000 children, and the rate of visits to emergency departments was estimat- ed to be six to 27 per 1,000 children (Fiore et al., 2009). For children, the risk for severe complications from sea- sonal influenza is highest among those younger than two years of age (Fiore et al., 2011).