Rates of seasonal flu are usually high amongst children: 20-30% of the overall population of children and up to 50% of children in daycare contract flu every year. Children with cardiac, respiratory and neurological diseases have a high risk of severe flu and flu-related mortality. Despite low overall mortality rates in the general population of children, it is important to remember that up to half the cases of flu-related mortality occur in children who were previously healthy. Most children hospitalized because of flu are aged under 1 year (annual hospitalization rate: 10-100 out of every 10,000 children depending on influenza season and geographic region). Hospitalization rates amongst kindergarten age children are similar to those seen amongst the elderly.