I don’t know if this will help, but I saw a show about the plague on PBS. There is a theory that through DNA certain people can actually become immune to certain diseases. They found through family trees, cadaver research, and wittiness accounts that some people should have contracted the plague but did not. Research today showed that the same thing was true today with certain individuals and HIV. You can check out PBS.org for more info on it if you think it will help. There should be some info on the website, but it was on last year so it may be tough finding it. Good luck!

1. it was probably a different string of the virus. The virus probably didn’t affect the fleas because it probably didn’t mutate to become one that would harm flees.

2. I think its gone and if it isn’t i think we have a vaciene or cure or something…