There Is No Vaccine In The Book
A huge portion of the movie is spent trying to develop a vaccine for the zombie apocalypse, and by the end of the film, one has been developed. Huzzah! But the book is very different. It’s not that there isn’t a vaccine in the novel. There is. It’s just that it doesn’t work. In the novel, a vaccine called “Phalanx” is rushed out to the market, and people begin to think that things might turn out alright, but it turns out to be a placebo. At least for the zombie plague, it is.
Phalanx actually worked fine on rabies, as the disease was, as mentioned earlier, thought to be a form of “African Rabies.” So, like the last point, the vaccine in the book is just even more biting social commentary, which is all but lost in the film adaptation.