World Battle II: 6 key variations between the e book and the film
There is no vaccine in the book
Much of the movie is spent developing a vaccine against the zombie apocalypse, and one was developed at the end of the movie. Huzzah! But the book is very different. It's not that the novel doesn't contain a vaccine. There are. It's just that it doesn't work. In the novel, a vaccine called "Phalanx" is launched and people start to think things might be fine, but it turns out to be a placebo. At least for the zombie plague, it is.
Phalanx actually worked well for rabies because, as mentioned earlier, the disease was seen as a form of "African rabies". Like the last point, the vaccine in the book is just an even more snappy social comment that is all but lost in the film adaptation.