Update: influenza activity--United States, September 30, 2007-April 5, 2008, and composition of the 2008-09 influenza vaccine.

摘要

This report summarizes U.S. influenza activity since September 30, 2007, the start of the 2007-08 influenza season, and updates the previous summary. Low levels of influenza activity were reported from October through early December. Activity increased from mid-December and peaked in mid-February.