>> reporter: it's super contagious. it's spread through the air. >> reporter: i brought cbs 'jon lapook with me to newark airport. >> if you just touch the screen, you can pick up the measles virus if it happens to be there. the good news is somebody who is here today doesn't have to worry. the measles virus only lasts two hours or less, even on the surface or in the air. >> reporter: so everyone who was here march 12 needs to be concerned. >> they said it was between 12:45 and 9:00 or so. >> reporter: i was here. >> uh-huh. >> reporter: i was here. >> well, you look pretty good. were you immunized? >> reporter: i was imnilessed. >> and that's the best thing you can do. >> reporter: how do you know you have it? >> it can be truckie, a sore throat, runny nose, and maybe pink eye and fever and then you come down with the classic rash. one of the tricky things sucan be infectious four to five days before you even come down with symptoms. so people may not even know that they have the measles and they're walk around and they're spreading it. >> reporter: people most at risk are children under the age of five, people with weak immune