You said flu! That's short for influenza caused by various strains of the influenza VIRUS!. Antibiotics are useless in treating it. However, Antibiotics are frequently used to treat secondary infections.
Prevention - keep away from people and wash your hands often, keep hands away from your face even though the virus is inhaled, and get an air sanitizer. Also insist that your boss send sick people home and supply Lysol to use in the work enviroment.
Again.. Antibiotics are worthless against flu viri!!!!!!!!
Load up on beta glucan, vitC, echinacia, and colostrum. Drink tons of water.
Good luck, I'm healthy as a horse but got the flu from someone unknown last month. Don't be afraid to tell a sick person to step back when they get too close and smack anyone who touches your food. I see so many young people eat off of each other's places in public.