that is what I was thinking too.....bacterial plagues vs AIDs virus......I don't get the connection unless the genetic proponent somehow mutated enough to be resistant to both...........sounds fishy to me....
I saw a documentary on PBS last year on the subject. The mechanism of infection appears to be the same for AIDS and the plague. I don't remember the details, but that's the reason why descendants of those immune from the plague are also immune from AIDS.