Centers for Disease Control and Prevention
Centers for Disease Control: Preventing the Flu: Questions and Answers
Find simple answers to several common questions about the flu including: "How does the flu spread?" "What are the symptoms of the flu?" "How long is a person contagious?" "What is the difference between a cold and the flu?" "At what age...
US Food and Drug Administration
Fda: Influenza Virus Vaccine Safety & Availability
The FDA provides a brief description of flu symptoms, an overview of the high-risk groups that ought to get yearly flu vaccines, and links to articles and statistics on flu vaccines from the year 2000 to now.