Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Failure to connect

The novel started off very well, creating a lot of suspense and an eagerness for the reader to find out what is the possible link between the two stories ( the autism causing vaccine and the toxic mine ). However, except perhaps to someone who is ignorant about biology, the author fails to fully explain the presence of prions in the vaccine. What are prions doing there in the first place ? I didnt know that prions were a basic element in a vaccine. Secondly, the vaccine was created with the intention to protect not to kill. So, it doesnt make sense at all.