Back in 2003, the Centers for Disease Control and Prevention recommended only certain populations get annual flu vaccinations; healthy children under 5 were not among them.
But did that make sense? The CDC-fundedEmerging Infections Programs (EIP) decided to find out. During the winter of 2003-04, the 10 EIP sites, including the Connecticut EIP at the Yale School of Public Health, tracked flu hospitalizations of young children and discovered that nearly three quarters of those admitted to the hospital were otherwise healthy and were not in a group recommended to receive the vaccine. Four of the five children who ultimately died of the flu had not been immunized. Those findings led the Centers for Disease Control and Prevention to recommend the following year that young children receive annual flu vaccinations.
http://medicine.yale.edu/news/article.aspx?id=15273
