Not necessarily. The mucous "snot" as you call it, has to get into the other persons mucous membranes, ie mouth, eyes, nasal passages. So yes it can if you have an infected idiot sneeze directly in your face while your mouth and eyes are open. Since this is not a third world shit hole with uneducated village people the chances of that are ridiculously low. Currently you are at much greater risk of getting Hiv from an escaped zoo Monkey