Clinical presentations for influenza and influenza-like illness in young, immunized soldiers.

Concern about respiratory diseases in soldiers increased in the late 1990s as production of the successful adenovirus vaccines stopped and the possibilities of an emergent pandemic influenza strain and use of bioweapons by terrorists were seriously considered. Current information on the causes and severity of influenza-like illness (ILI) was lacking. Viral agents and clinical presentations were described in a population of soldiers highly immunized for influenza.