Hi

Include some of prevention methods:

Wash your hands with soap.
Get enough sleep (because it keeps your immune system in top flu –fighting shape).
Drink plenty of water to flush out toxins .
Eat healthy foods which increase immune system (dark green , yellow , red , orange color fruits & vegetables , green leafy ).
Avoid alcohol (it is suppressant immune system & reduces your resistance).
Keep always in active (do some exercise or keep yourself very busy).
Avoid contact with sick people. (try to stay a few feet away from them ).