The book felt somewhat mediocre to me.
I was really expecting more of a "science" angle to this. 2 of the 4 "main characters" are scientists. Yet they don't do pretty much anything with the knowledge. The only time their degrees and position really even plays into anything outside of being involved in the initial infection, is being able to use the emergency blood sticker to park anywhere! The pathogen and how it works isn't examined by the doctors themselves pretty much at all, though eventually they get some second-hand talk about it.
On the character front, the whole "divorced parent worried he was going to lose his kid" and the crisis leading to his losing custody just felt very cheap and artificial. Ephraim himself though, as well as the Prof and Vasility are at least given decent backgrounds and have distinct voices. However, the 4th main character, the second in command of canary and the love interest, is pretty much given no voice and no important role. Is even saddled with the kid before the final fight.
Lastly, on the plot, it seemed silly that they were going around killing the 4 that were awake. Unless I missed something, that seemed like such a waste of time. You have hundreds of others out there, and you are going around killing a few at a time? It was absurd. Go and hunt the Master, or go and try to warn the public. Going around and killing those 4 was such a silly waste of time that had no significant effect at all on the spread. It would be like going and treating 4 flu victims in the middle of a flu outbreak and ignoring all other cases. Anyway, even if the Master had been killed, it still seemed like NY was completely fucked and therefore the entire US to follow. It was hard for me to care about whether or not the Master dies, knowing that it still wouldn't do much at all to stop the infected. Killing patient 0 of a flu epidemic does fuckall to stop it. Maybe I missed the Prof saying something about all of them dying if the Master did? Even if I did miss that, then that would be even more evidence that they should have been going after the Master initially, not going around to random homes.
Anyway, sound pretty negative but really I did enjoy it decently. Was just expecting more.