You could create a mod , that adds small chance that your character is immune to the zombie virus.
About 1 % humans are immune to HIV, so it wouldn't be so stupid.

Could you make a version that requires hydrocraft

You could add a recipe for a permanent cure but one that will take a lot more than the normal cure to discover. Or some pills you must take at a certain amount of time while you search the one use cure (like make the infection slower).

(with "one use cure" i mean the cure that this mod adds)

maybe be able to capture a live zombie or cut off its limbs so its safe to handle and it be a requirement for research of say behavior or something of the sort

@Eyepatch,
Blood of just killed zombie is the same. I will add that it must be fresh corpse.

@Your favorite Heavy,
Good idea. I will add that ingredients are comsumables and will slow the virus.
Now there is a game bug that API function setInfectionLevel() doesn't work. So I have to save all stats and injures, use function FullCure, and then add all stats and injures back. So I need a bit complicated code to avoid that bug. Just complaining...

@AussieWookie,
I don't use Hydrocraft. The mod is designed for vanilla. Tell me what items from Hydrocraft should I use and what rarity they have. I guess they will be ignored in vanilla if I add them to recipes.

@Klonix,
I'm not sure especially in multiplayer. On a specific server a player will die until they gets an immunity. ~100 new characters and no craft/tasks. But it's interesting idea anyway.

I have a few new ideas!

Inspired by viral hepatitis, malaria, rabies virus, HIV, measles, poliomyelitis and ofc influenza virus.

I'd like to make at least 2 types of virus: male virus and female virus. But it's a minimum that I want. May be more virus types and stages of immunity.

What do you think how to make it more interesting?

Perhaps you could make some part of your quest require the player to go to a hospital, police/fire station, or military base? Maybe they need some state of the art technology. The military could have been distributing/transporting certain parts/equipment for the cure. I'd be fine with having to travel miles to get to some machine in a hospital that has the sole purpose of creating the cure.

I dunno how in depth you'd want to go, but maybe once they add the clothing update, you could make it so that random zeds with the correct uniform have a small chance of carrying it. You could also make a new profession that was a biochemist trying to find the cure. The player could start off with advantages pertaining to the cure.

While I personally haven't tried the addon yet, I think a good idea would be; a military lab is overrun and the infection ward contains the cure, but the sensor on the door requires a person to have a viral load of 50% (aka state of infection ingame as over 50%) to open the door, the major catch, there is a single facility located in every town and only one has the cure. The only way to reliably check every facility is to grab (X) amount of suppresents out of the rooms inside if there is no cure, and use them to give you time to get to the next facility.

Is there military lab/base in vanilla game?

i originally meant like contact a map maker, and maybe have him help you make this into a bigger project.

@Is there military lab/base in vanilla game?
=> Not, right now. You may have to use some other mods (Secret Military Base seems indicated).

After test ; maybe you can swap the ingredient "Peach" for something that can be growth ?

I'm pretty sure the peach was chosen for some good IRL reason but...

[Context] I've start to use that mod on an old game with a remove rotten food setting which alrdy triggers (remove rotten was set to 90-100d can't remember exactly, and the game itself is in the 6th month now). I'm in the middle of winter. [/end]

So, i can't get the "Grape Leaves" but i still can wait for winter to end and Foraging tables again allows "Grape Leaves" to be harvsested. But i just can't get peach ; no way to growth them with Agriculture (i'll check for mods that allows that) and all rotten peach across the world game has been removed. For that reason, the questline is a dead-end for me (well, it's really PZ feeling in a sense).

You may craft Allergic Extract using rotten peach.
The recipe is random but it always requires something like that which can't be grown.

That's the issue (i know i could use rotten things in recipes) : there's no "rotten" anything past the "Remove Rotten food" point :)