Turn Off Infection in Project Zomboid (Build 42.19): Transmission = None

Build 42.19 · turn off Knox virus (Transmission = None)

What “turn off infection” means

In Project Zomboid, players usually mean the Knox virus (zombie plague), not ordinary wound sepsis or food sickness. Sandbox Zombie Lore controls the plague:

Method A: Sandbox / server settings UI

Prefer the in-game controls when you can. They write the same sandbox values without hand-editing files.

Single-player custom sandbox

1. Start a new game with Custom Sandbox (or open sandbox options if your flow allows editing before start).
2. Open the Zombie Lore section.
3. Set Transmission to None.
4. Optionally set Infection Mortality to Never if you also want the virus timer never to kill.
5. Start the world. Changing these mid-save is not always exposed the same way; multiplayer servers use the server sandbox file or admin sandbox tools instead.

Multiplayer Host / dedicated server

1. Open your server settings (Host → Edit Settings / Manage Settings, or the dedicated panel’s sandbox editor).
2. Find Sandbox → Zombie Lore.
3. Set Transmission = None (core).
4. Optionally set Infection Mortality = Never.
5. Stop the server cleanly if it is running, then start it again so clients load the new sandbox values.

Method B: Edit the server sandbox file

Use this when the Host UI is unavailable (remote dedicated box, scripted deploy) or when you need to confirm the exact values on disk.

Where the file lives

• The directory is Users (with an s), not User.
• The file name includes your server name (for example servertest_SandboxVars.lua), not a generic sandbox file with no server name.
• If the server runs under a different system user or container home, use that user’s Zomboid/Server/ tree.

Safe edit steps

1. Stop the multiplayer server completely.
2. Copy the server sandbox file to a backup (for example add .bak to the name).
3. Open the file in a plain-text editor.
4. Find the Zombie Lore block (ZombieLore = { … }).
5. Set Transmission = 4. Optionally set Mortality = 7.
6. Save the file. Confirm braces and commas still look valid.
7. Start the server again and join with a test character if you can.

-- Inside <ServerName>_SandboxVars.lua (other Zombie Lore fields omitted)
ZombieLore = {
    -- ...
    Transmission = 4, -- None: no new Knox virus from zombie attacks
    Mortality = 7,    -- Never: optional; already-infected do not die from the virus timer
    -- ...
},

Transmission and Mortality values (Build 42.19)

These match the English sandbox menu labels. Numbers start at 1 in the order shown in-game.

Gameplay impact

With Transmission = None, players stop treating every scratch as a potential soft-lock. Combat mistakes still kill through bleeding, fractures, exhaustion, and being swarmed—only the Knox infection channel is closed.

• Easier long-term multiplayer: fewer forced character resets after one bad bite.
• Lower tension: the signature “you are already dead” pressure is gone; some groups prefer that for RP or building servers.
• Not invulnerability: zombies still damage and can overwhelm you. Ordinary wound infection and food sickness are separate systems.
• Existing infected characters: Transmission alone does not rewrite history. If someone is already on the virus clock, use medical or admin tools for that case, or set mortality to Never if your goal is “never die from the timer.”

Related guides

• Broader infection guide — mods, cheats, and longer context around Knox vs ordinary illness.
• Server administrator tips — backups, sandbox, and day-to-day host tasks.
• Server survival admin notes — additional multiplayer admin practices.
• Server memory planning — Host vs dedicated heap settings on Build 42.19.