Undeads are walking UN

It is the year 20XX and something bad happened to Earth and humanity, but much worse to humanity to be precise. The thing it has happened, it is known as a zombie apocalypse by the modern generation.
It presents the stories of a few groups of survivors across the world who are either going to stay among undeads, zombies, climbers, swimmers, vomitrons, flamers and tons of other types of zombies, or try their luck to run on inhibited islands with or without military help and live safely until everything comes down. Eventually.