CDC

http://www.cdc.gov/flu

http://www.cdc.gov/flu/espanol/

http://www.cdc.gov/vaccines/

American Public Health Association

http://www.apha.org/programs/fluresources/

Department of Defense

http://www.geis.fhp.osd.mil/GEIS/SurveillanceActivities/Influenza/influenza.asp

World Health Organization

http://www.who.int/topics/influenza/en/         

http://gamapserver.who.int/GlobalAtlas/home.asp

American Lung Association

http://www.lungusa.org/site/c.dvLUK9O0E/b.1833363/k.61C9/Influenza_Flu_Center.htm

NIAID

http://www3.niaid.nih.gov/topics/Flu