What is this movie, set in America?

It revolves around a couple, he is home she is in the city and some biological event takes place, she gets covered in dust etc. She is supposed to stay in the city for quarentine but flees home, he hears about it on the radio or something and seals up the house as he is told to do. She gets home, he wont let her in, she eventually busts in frustrated and he seals off a room for her to use. I wont go into more details because if you know the movie this will be enough info to help figure it out.

I can't remember what it's called, please help.