Interactions at School
Before and after school you get 2 options
1). Choosing the "weird girl" you'll interact with Tracie and infect her.
2). Choosing "go to class" you may get the event where a fight breaks out and you have to choose to intervene, ignore or "Cat fight" join in. By joining in you will be sent to the school Nurse. If you have not infected her there is nothing to do except go to the teachers lounge. If you have infected here you will be able infect her further.
1). After school you can go to the teachers lounge and interact with Claire, if she is not there this gives you the chance to infect the room, then go home.
2). Go to Steve's house and infect him and his parents.