Dawn begins ten years after 2011's Rise in the rebooted Planet of the Apes series, after a man - made virus dubbed simian flu spread globally, killing millions. (tampabay.com)
Similar to the mid-credits sequence in the conclusion of Rise of the Planet of the Apes, this promo video takes the stance of a PSA, warning humans about the risks of Simian Flu. (silverscreenriot.com)
Also worth mentioning is that the game also has a special Simian Flu plague which ties in with the Dawn of the Planet of the Apes movie. (wolfsgamingblog.com)