(AP) -- People hospitalized in the United States for swine flu are turning out to be younger than is typical for regular flu.

U.S. health officials say the median age for confirmed hospital cases is 15.

Dr. Richard Besser of the Centers for Disease Control and Prevention said it's not clear why that group is so young. He said it might just be that younger people have tended to get sick first in the outbreak. Or maybe older people have some greater level of immunity against the .

The age range for those in the hospital is eight months to 53 years. The CDC says there are at least 35 people hospitalized for the new .

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