Does anybody know the name of this movie?

I can't remember the name of a movie I saw a little while ago. The movie was centered on a group of four teenagers about college age. There had a been an outbreak of a deadly virus and it was highly contagious (anything an infected person touched had to be sanitized with bleach). It seemed like an end-of-the-world thing because most had been infected or died. At one point, the teenagers picked up a little girl and her father, but they abandoned the two. Also, they eventually found a car with two older women (Christians by the Jesus fish bumper decal) but one of the teens shot them because they were refusing to help their group. I remember the four wore surgical masks decorated with different smiles in Sharpie. At the end, only two of them had survived and found refuge on a beach to wait for the virus to die out. This is all I remember, but I can't remember the name of the movie. Does anybody know it?