Another Young Adult Post-Apocalyptic Novel

Authors are jumping on the post-apocalyptic band wagon. There are many good ones out there and Ashes, Ashes by Jo Treggiari promised to be one. However much potential the book had, it left me thinking this book is not finished yet. The story is set after a plague decimates the majority of the population, mostly adults and some children who were not vaccinated due to their generations reluctance for vaccines. The heroine is the exception. She was not vaccinated because her parents were against vaccines after the loss of a child. Throw in a mad scientist whose personality resembles Jekyll and Hyde and her minions in hazmat suits kidnapping people and you think this might work. But unfortunately, the ending was too clean and left you asking "That's it?"