This is one of the episodes that was originally scripted with Arturo and had to be rewritten after John Rhys-Davies was fired. It was modified without Kriozere's input. Aside from the fact that the cause of zombification is never explained, Kriozere's draft differs in that Debra is the only survivor with Arturo rushing to develop a cure. Tassler was obviously added to bring in someone who could produce an inoculationin in the absence of the Professor.
Kriozere originally wanted Wade to be infected, but it was changed to Quinn after meetings with the show's producers.