Coughing is the way our body tries to get rid of foreign bodies out of our lungs. I wonder why we should prevent our body to cough, even if it allows us to get rid of some virus. I understand that it slows down the spreading of the disease, however I don’t understand, from an evolutionary point of view, why this feature was kept. If it is so disadvantageous, why would this trait survive ? If it’s advantageous, why do we suppress it ?