Viruses!

A datapack that adds new disease system!
It is fairly simple, every now and then, you get infected and after some time, you have a 50/50 chance to get cured, or make disease mutate.

For now, there are only 4 disease with different effects:
Disease 1: player hunger increases, when it is mutated: the hunger is even worse with new effects, blindness and slowness - this disease isn't very dangerous on its own, but when, for example, fighting, it can be fatal.
Disease 2: player gets weakness, when it is mutated: weakness is stronger and lasts longer with new effect, slowness - the same as "disease 1", on it's own, it doesn't do much, but in some situations, it can be very dangerous.
Disease 3: player now gets poison, when it is mutated: poison doesn't get any stronger, but there are (like always) new effects: strong hunger and nausea - this time disease can actualy damage player on it's own, so better watch out!
Disease 4: at first, player only gets poison, so it can be mistaken for disease 3, but when it mutates: now instead of poison, player gets wither with hunger - this is the worst disease in this datapack, not only it is strong, but it can actualy kill the player!