Plague Inc. Prion Brutal Guide / Walkthrough

The Prion plague type is the 5th unlock-able plague in Ndemic Creation's game, Plague Inc. Prion is unlocked by successfully finishing the Parasite plague in either normal or brutal difficulty(Here's a Parasite Guide on brutal difficulty).

The Prion plague type is slow and by this I mean that the abilities, transmissions, or symptoms you evolve take quite awhile to take effect. Similar to every other plague type it has its own unique abilities. Prion's unique ability is Neural Atrophy. Its description says that it "makes complex tasks harder", this basically means it slows down the progress of the cure being made to stop your plague. Neural Atrophy can be evolved three times, the effects slightly better than the previous one but they do stack. In Prion's description it also states that this plague type is subtle and extremely complex, meaning it won't easily be detected by having a few symptoms.

In my experience experimenting with this plague type, it starts out slow at infecting people and moderately increases its infectivity based on the transmissions or symptoms you evolve. I think it also has a hard time spreading in hot regions.

This guide was made without the use of genes, so experiment with them if you want to get a much better score. Since this guide is based on brutal difficulty, it can also be used on the lower difficulties with much more ease.

Anyway, let's start this guide.

Start in China

  • High population, an airport, and a harbor. Ideal place to start a brain-hidden plague.
Evolve the following in this order:
  • Air and Water transmission to level 2
  • Heat and Cold resistance
  • Drug Resistance 2
Wait for the whole world to be infected. Devolve any mutated symptoms that pop-up and stop once it starts costing DNA to devolve.
(You can choose to devolve one mutated symptom if you haven't been able to infect the entire world yet. It's worth it since it'll only cost one DNA)

Once the whole world is infected start evolving symptoms. I recommend evolving these symptoms in this order since they have high enough lethality to eradicate humanity before the cure completion even reaches 25%.
  • Cysts
  • Abscesses
  • Systemic Infection
  • Coma
  • Total Organ Failure
  • Tumours
  • Internal Hemorrhaging
  • Hemorrhagic Shock
  • Necrosis
Once you get Total Organ Failure you can opt to slow down the cure instead of focusing on your plague's lethality. I just prefer killing people faster.

Here are my stats on the two games I did with Prion on brutal difficulty.
1st Game - 856 days| 17% Cure Completion| 4/5 Biohazards
2nd Game- 987 days| 23% Cure Completion| 4/5 Biohazards

Here's a better strategy than the one posted above

Gene Setup:
Cytochrome Surge
Genetic Mimic

  • Start in India
  • Evolve Coughing
  • Evolve Air and Water 2 then Extreme Bioaerosol
  • Cold and Drug Resistance 1 then evolve Cold and Drug Resistance 2
  • Wait for the whole world to be infected while devolving any mutated symptom.
  • Evolve the following this this order: Sneezing, Immune Suppression, Total Organ Failure, Coma, Systemic Infection, Tumours, Internal Hemorrhaging, Fever, Hemorrhagic Shock, Necrosis, Paralysis, Inflammation, Seizures, then Insanity.
TIP: Evolve the following as soon as you have the DNA to do so.
These are the stats I had when I used this strategy
608 days
11% Cure Completion
5/5 Biohazards

So there you go, have fun with experimenting with gene setups and getting a higher score. If you guys have any tips or strategies that are better, post them at the comments below and I'll check them out. I'll include the good ones in this guide. Have fun ending humanity!


  1. Worked all good thanks

  2. Try starting in New guinea and upgrade livestock first. It's interesting.. like Kuru.

  3. I won. :)
    Time: 650 days
    Cure: 13%
    4/5 biohazards

  4. That was easy, 595 Days, 6% cure and 4/5 biohazard :)

  5. Help! I've been battling this stupid mode and can't seem to win. I have no problem getting the whole world infected, but as soon as I evolve the symptoms (even the deadly ones like coma and total organ failure), the cure research ALWAYS beats me. I've tried evolving the drug resistance and genetic hardening and all that stuff, and it STILL beats me. I'm not giving up... I'll never give up... *angry huffing*

  6. neither of these work and it's really starting to piss me off. Test your guides more than once.

  7. It seems the they have made some changes in the Game, the first guide is not working at all for me. The second one only with slight changes at the end, stats:
    870 days
    80% cure

  8. I'm pretty sure they tested it more than once, it's simply outdated.
    But you can still use it as help to find your own way ;)

  9. nope, doesnt work :(. they probably changed the game somewhat. i have 120 odd dna points before escalating symptoms but the cure is freakishly fast!! Even full neural atrophy after total organ failure didnt work:(

  10. I had to use a genetic reshuffle because the cure reached 100% and barely won with 88% cure done

  11. any suggestion for prion brutal mode without gene modification? The prion cant kill fast enough and the cure is too rapid

  12. Strategy #2 worked perfect! Thanks!

  13. Sorry but from where u get all DNA the cure always success before DNA harvesting from kills people ... Additional DNA start when population falls below 5 billions at this point the cure is 95 in my game

  14. Not fucking working...

  15. Type in "how to beat "mode you want" walkthrough". Ashleigh is the best one.