When you are flying, you have no idea who is around you and you are stuck in a confined place. Personally, I would never fly with an infant in a plane when there is a flu epidemic. You can't leave the plane if someone around you starts coughing a lot during the flight. It's not a risk I would take. My 14 year old son is home from school with the flu (he had the flu shot), it is a bad flu and he is just laying in bed very lethargic. Not worth a trip going in a plane, IMO.