I've read this book for two different book clubs, with about 6 years between each reading, and on both occasions I've come away feeling a bit 'meh'. On the plus side, it's easy to read, the characters have distinguishable names (e.g. no 'Jon' and 'John' who are completely different characters) and all the threads that run through it are tidied up at the end. Each character is distinctive and has their own flaws and background.

On the downside, there isn't really anything particularly new or special in this book. A virus that spreads rapidly and kills off >95% of the population has been done before, and it's unconvincing to have an infectious agent with an incubation period of a few hours which kills within a day - people would die before they could pass it on (at that speed you'd have a plane full of bodies on a long-haul flight).

The big problem I have though is that this is supposed to be a post-apocalyptic book, but at least half of it is set pre-apocalypse, achieved through the overuse of flashbacks. Used judiciously, flashbacks can add something to a story, but when they're overused they interrupt the flow and become jarring - better to start with the original events and proceed in chronological order than to jump backwards and forwards.

Like the other reviewers who have given this 1 or 2 stars, I'm struggling to see what I'm missing here that's causing the majority of reviews to be 4 or 5 stars and gushing with enthusiasm.