User blog comment:BannedLagiacrus/Monster Hunter Ecological and Lore Info Blog/@comment-6050823-20160914023732

Discovered more about the Apex Monsters.


 * Apex Monsters were able to get away from most of the Frenzy Virus spread out by Shagaru Magala in time in order to live on.
 * By leaving away early enough, the Apex Monsters didn't feel all the full potency of this stronger strand of the Frenzy Virus, including the reproductive spores.
 * They're affected by the Frenzy Virus, but not as extremely as the Frenzy Monsters.
 * Apex Monsters gain an immunity to the virus, while infected, and eventually turn to their old self if they live long enough.