Station Eleven by Emily St. John Mandel:
Clark walked the length of the airport, restless, and was stunned to see that the security checkpoints were unmanned. He walked through and back three or four times, just because he could. He’d thought it would be liberating but all he felt was fear. He found himself staring at everyone he saw, looking for symptoms. No one seemed sick, but could they be carrying it? He found a corner as far from his fellow passengers as possible and stayed there for some time.