man flu is a way of saying you have a common cold, but to make you feel better they add in the word flu for pussys who think they have the flu because its nothing like a propper flu but a bit worse than a typical common cold. the cure is to htfu.
antibiotics dont work for virial infections, so by taking them (and the doctor giving them when you dont actually need them means they are fast becoming useless and if you (as a people) keep taking them we might be back to dying of the common cold or similar again in the future