Each year in the United States, about 200,000 people are hospitalized due to flu complications; children 5 years old and younger make up 20,000 of those hospitalized; and 36,000 people die from seasonal flu.

While no one knows exactly what will happen with 2009 H1N1 influenza (previously known as swine flu) this flu season, as many as one in four Californians could be affected with mild, moderate or severe symptoms.

Seasonal flu vs. H1N1 flu: What's the Difference?
H1N1 vs Seasonal flu: See a side by side comparison (PDF)