The flu season is off to an early start and hitting areas across the country. Preventing the flu is tough enough, but the task is more difficult for some.
FOX's Colleen Cappon has who's at the greatest risk in today's "Housecall for Health":
Scientists are trying to find why some people are more susceptible to the flu. Researchers at Northwestern Hospital have been analyzing different influenza strains since 2009, and say the first seven days of becoming ill are the most critical - and catching the virus is getting easier every year.
Children younger than five are at the highest risk, along with seniors over 65.
Housecall for Health, I'm Colleen Cappon, FOX News Radio.