Has anyone ever tried this?
When I was a kid growing up in lovely Staten Island circa late 80s, we played a version of this but we called it King Tag. One person was "it" and had to tag others who then joined his side until there was only one person left trying to escape. Your only defense was a gym sock filled with baby powder that you could attempt to bludgeon the "zombie" with. Though we never called 'em a zombie. The rules weren't very drawn out but we were only fourth and fifth graders not fancy college students.
It sound like a version of "Virus", it has the same kind of rules. One person is it and everyone he touches becomes infected and they go out to infect more people until the there's only one left, the one left becomes the anti-virus and then tries to spread the cure amongst the infected. Then the game just goes back and forth like that until everyone gets bored or drunk and stops playing.
Pretty cool game, in my opinion. It clearly has no more to do with school shootings than D&D has to do with suicides.