Frozen Virus Scenario Logo.png "A giant virus, frozen deep in the Siberian permafrost, has thawed and infected an unknown victim.
Dormant for over 30,000 years, it was last active at a time when mammoths and Neanderthals roamed the world. It's ancient genetic structure pre-dates homo sapiens but it's DNA has been severely degraded.
Does it have what it takes to send humanity back to the stone age?"

— Plague Inc., Frozen Virus introduction paragraph.

The Frozen Virus scenario was introduced in Mutation 1.8 as a Scenario. It was later introduced to the PC as a beta build for Evolution 7 on May 20, 2014, along with the rest of the missing Mega Mutation 8 scenarios. It possesses the ability to invoke forced evolution in its hosts, causing them to "regress" to a more primitive state.

Its default name is Pithovirus in-game, after its eponymous real-life counterpart.


The plague starts with Amoeba 1, Mandibular Strain, Drooling, Cold Resistance 1, Cold Resistance 2, and Cold Resistance 3 already evolved. It automatically starts in Russia (Siberia).


  • Amoeba 1 - Amoeba susceptible to viral infection and spreads primarily through freshwater and saltwater. Increases infectivity (You automatically start with it).
  • Amoeba 2 - Virus manipulates amoebal DNA, allowing host amoeba to thrive in warm body parts of animals. Increases infectivity. (Unlocks all other types of transmissions)
  • Amoeba 3 - DNA reshuffled to allow host amoeba to survive and spread in animal faces, increasing infectivity in poor, rural countries.
  • Bird 1 - Birds become susceptible to infection. Avian carriers increase infectivity, land transmission and mutation.
  • Bird 2 - Avian brain tissue compromised causing birds to attack other species. Increases mutation, infectivity, and land based transmission.
  • Rodent 1 - Common flea susceptible to infection. Increase infectivity, especially in urban regions and mutation.
  • Rodent 2 - Rodents directly susceptible to infection. Increase infectivity, especially in urban regions and mutation.
  • Livestock 1 - Livestock susceptible to infection. Increase infectivity, especially in rural regions and mutation.
  • Livestock 2 - Wildlife susceptible to infection. Increase infectivity, especially in rural regions and mutation.
  • Insect 1 - Insects susceptible to infection. Carrier insects increase infectivity, especially in hot climates and chance of mutation.
  • Insect 2 - Increases rate of transfer between insects. Increase infectivity, especially in hot climates and mutation.
  • Water 1 - Pathogen can survive outside the body in fresh, warm water. Increase infectivity, especially in humid environments and ship transmission.
  • Water 2 - Pathogen able to survive in chemically treated water. Increase infectivity, especially in humid environments and ship transmission.


Tier 1

  • Mandibular Strain - Moderate pain in mastication muscles, especially when eating, and periodical jaw clicking (can't be devolved, you automatically start with it).
  • Drooling - Occasional intemperate drooling when sleeping or eating. Increases infectivity slightly (can't be devolved, you automatically start with it).
  • Anaemia - Deficiency in the levels of heme contained in the hemoglobin which can lead to hypoxia in the organs.
  • Cysts - Painful lumps containing pockets of the pathogen. Slight chance of bursting which can spread disease.

Tier 2

  • Edentulism - Severe gum infection causes teeth to fall out.
  • Memory Loss - Recent memories become nebulous in patients, replaced with vague historical recollections. Slows cure progress.
  • Jaundice - Accelerated viral reproduction in the liver results in bilirubin build-up, causing yellowing of skin, eyes and mucus membrane. Increases infectivity.
  • Skin Lesions - Breakdown in the epidermis causes large open wounds which significantly increase infectivity.

Tier 3

  • Carnivorous Denticulation - Hormone changes trigger growth of carnivorous teeth and consumption of raw meat. Poor dental hygiene increases infectivity.
  • Immaturity - Reduction in hormone levels causes immature and antisocial behavior, reducing cure research. Lower levels of hygiene cause infection.
  • Malignant Ascites - Accumulation of fluid in abdominal cavity due to severe cirrhosis. Can be lethal.
  • Abscesses - Pockets of infected flesh are painful and act as breeding grounds for the pathogen, increasing infection rates when burst.

Tier 4

  • Bone Dysplasia - Relentless bone growth with high mineral density results in severe musculoskeletal stress; lethal in many cases. Broken skin increases infection. (can't be devolved)
  • Aphasia - Progressive loss of brain cells damages parts of brain responsible for language and understanding. Makes cure development harder. (can't be devolved)
  • Hepatic Failure - Chronic replacement of normal liver cells with scar tissue causes liver to fail, resulting in rapid death.
  • Systemic Infection - Pathogen affects multiple organs and tissue types, causing body-wide infections that spread fast and can be fatal.
  • Tumours - Pathogen disrupts cell growth pathways, causing uncontrolled, eventually fatal tumour growth.

Tier 5

  • Cranial Elephantitis - Increased bone growth places pressure on the brain. Trauma makes cure development significantly harder and can be lethal.
  • Aggression - Confusion and immaturity results in lethal primal aggression towards others. Cure progress significantly slowed.

Tier 6

  • Hemorrhagic Shock - Failure of the heart to pump effectively causes oxygen deprivation, loss of consciousness and death.
  • Neanderthal Regression - DNA recombination destroys logical and emotional brain function, leading to complete regression to Neanderthal state (can't be devolved).

Location of Each Symptom


DNA Repair

Having spent the last 30.000 years dormant and deep-frozen in permafrost has done no favors on the Frozen Virus' DNA. The genetic code has been severely degraded and needs to be repaired in order for the virus to fully unlock its potential. This is done through the DNA Repair tree of abilities.

These Abilities unlock more symptoms when evolved, gradually granting access to the entire Symptoms tree. They can only be taken in order, starting with the 'DNA Repair 1' trait, which starts off available but not evolved at the start of the game. None of them can be devolved once evolved.

DNA Repair 1 Initial repair of low-level protein strands damaged during dormancy. Restore ancient symptoms and ability to stabilize in warmer environments.
DNA Repair 2 Partial repair of low-level protein strands damaged during dormancy. Restore ancient symptoms and ability to resist basic immune responses.
DNA Repair 3 Full repair of low-level protein strands damaged during dormancy. Restore ancient symptoms and ability to withstand higher temperatures.
DNA Repair 4 Initial repair of high-level protein strands damaged during dormancy. Restore ancient symptoms and ability to resist advanced immune response.
DNA Repair 5 Partial repair of high-level protein strands damaged during dormancy. Restore ancient symptoms and ability to survive in hot environments.
Full DNA Repair Viral DNA fully reconstructed, giving access to entire genetic code from Neanderthal era. Can now entirely reshape human temperament.

Cure/Drug Resistance Abilities

These abilities will affect the plague's resistance against treatments and drugs. They will also slow down cure creation speed and increase more work required to create a cure.

Drug Resistance 1 Pathogen becomes resistant to class 1 and 2 antibiotics. Increase effectiveness in wealthy countries.
Drug Resistance 2 Pathogen develops resistance to class 3 and 4 antibiotics. Increase effectiveness in wealthy countries.
Genetic Hardening 1 Pathogen becomes harder to analyse in the lab. Decreases future research speed.
Genetic Hardening 2 The pathogen does not reproduce in lab conditions. Decreases future research speed.
Genetic ReShuffle 1 Pathogen DNA strands reassembled. More work needed to develop a cure.
Genetic ReShuffle 2 A new strain of the pathogen now exists, increasing the work needed to develop a cure.
Genetic ReShuffle 3 Multiple strains of the pathogen now exist, increasing the work needed to develop a cure.

Other Abilities

These abilities affect the plague's ability to spread in different environments.

Cold Resistance 1 Pathogen is naturally used to withstanding cold temperatures and climates. (Can't be devolved, you start with it)
Cold Resistance 2 Hardened virus capsid ensures pathogen survival in extremely cold environments. (Can't be devolved, you start with it)
Cold Resistance 3 30,000 years of surviving beneath layers of ice have completely solidified virus's lipid covering, ensuring survival at sub-zero temperatures. (Can't be devolved, you start with it)
Heat Resistance 1 Pathogen evolves to withstand hot temperatures and climates.
Heat Resistance 2 Pathogen evolves some resistance to high temperatures. Increased effectiveness in hot climates.
Heat Resistance 3 Pathogen avoids cellular breakdown in high temperatures. Increased effectiveness in hot climates.
Ice Resistance Pathogen able to survive and spread in crystalline sea water when ice melts. Increases infectivity by sea, and is harder to detect.


  • If the player wants all symptoms available, they should keep evolving DNA Repair tree traits as every trait in that tree unlocks more symptoms, up to Full DNA Repair which unlocks the entire symptoms tree.
  • If the player evolves Neanderthal Regression, then any and all countries that are 100% infected will not be allowed to contribute to curing the virus, and will instead revert/regress to a Neanderthalic state.
  • Since the virus begins in Russia, players should plan out their strategy to reflect the sea traffic of Russia.
  • The virus is already by nature highly resistant to cold climates, making it very capable of handling cold countries that otherwise would be hard to infect such as Greenland and Iceland. However, heat is still an issue, and as such, heat resistance abilities should be still be developed, as otherwise the virus will have difficulty taking on hot island countries like Caribbean and New Guinea. Especially so since they only have ports.


  • The Frozen Virus is based off of a real-life virus that itself is part of a special group of viruses known as Giruses, or Giant Viruses, due to their extreme size. It is not known if it is actually infectious or if it poses a threat to humans since it was recently discovered.
    • Some believe that these viruses could potentially elongate human life. A Russian scientist named Anatoli Brouchov injected himself with one of these ancient viruses, reporting that he hadn't had a cold or flu in two years, as well as higher energy levels.
  • Modern day humans did not actually evolve from Neanderthals (they actually both evolved from Homo Heidelbergensis and are separate species), and while they do share common ancestry they are in fact two branches of the genus Homo. Homo Sapiens Sapiens is the modern-day human and Homo Sapiens Neanderthalensis is the Neanderthal. The two species once inhabited parts of Afro-Eurasia together but as food became scarce and the climate became colder due to the then-ongoing ice age reaching its peak, the two species presumably came into competition with each other and the bigger Neanderthals eventually succumbed and went extinct around 40.000 years ago, while the smaller Homo Sapiens Sapiens survived and eventually thrived. Thus, humans cannot "devolve" to Neanderthals since they never evolved from them in the first place. Instead, the Frozen Virus' disease can be viewed as a form of forced evolution towards a more primitive state. This is also probably because many people think of Neanderthals as the ancestor of modern humanity so it would make more sense to more people.
    • That being said, there are cases where Neanderthals interbred with the ancestors of modern day humans, but it was not widespread enough to overcome their Sapiens Sapiens ancestry. Modern-day humans only have about 1-4% Neanderthal DNA in their genes.
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Frozen Virus Scenario Logo.png Frozen VirusScenario global warming.png Global WarmingScenario develop this.png Golden AgeScenario global cooling.png Ice Age
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