Scientists at St. Louis University said many older people have a built-in immunity to the H1N1 virus because a similar virus circulated some 70 years ago. The proof is in the numbers.

More youth and people in their 30s and 40s are getting sick with the swine flu than older adults. To solidify that claim, the Centers for Disease Control and Prevention shows that middle-aged people are being hospitalized at a higher rate for swine flu than regular flu. This means elderly people are being hospitalized at a lesser rate for swine flu, but still have normal hospitalization rates for the regular influenza virus.