The book complicates the question of whether there can be more Spark wasps. From the information in the comic, we assumed they'd need to reverse engineer Slarlantz' wasp (which was not used under controlled conditions as planned) to get more, which would be slow and difficult. However, in the book, Selnikov reveals that the fact that they don't affect Sparks is due to an agreement between Lucrezia and the Order, not an innate limitation. What I take from this is that Klaus' wasp is forever unique, but Lu could make Spark wasps whenever she chose. I wonder 1) if the uniqueness of this wasp is going to be significant and 2) what else was in Tarvek's spies' report about it.