If you get hit with the flu this winter, your genes may determine how well you recover.

Scientists are uncovering evidence that helps explain why the flu is deadly for some people and hardly affects others. It is information that could prove to be vital if the bird flu virus becomes pandemic.

It's a fall tradition; the flu shot line-up, with the young, the old, and people with heart disease and other conditions that may compromise their immune system.

Sherif Mossad, M.D., infectious disease specialist, said, “We can prevent a lot of deaths and hospitalizations as well as visits to health care providers by getting these high risk people immunized."

Now there is evidence a person's genetic make-up may put them at risk. Scientists have discovered different breeds of mice produce different immune reactions to the flu.

Animals that were more likely to die from the winter ill had an overactive immune response, compared to the strain of animals that only developed mild illness.

Scientists are now searching for genetic differences in the immune system noting that the information could help explain why some seemingly healthy people develop severe complications from the flu and could help save lives in the event of a pandemic by identifying those who need to be first in line for vaccines and therapies.