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Influenza A

Influenza A

The Shapeshifter's Kit

Influenza A keeps mutating its own shots, and every few seconds it fires something different.

The Shapeshifter · Starter

Influenza A

The virus every lineage starts as. Its shots keep mutating between four types, its Antigenic Shift fires every mutation at once, and its Pandemic ultimate infects every cell nearby.

  • Role: The Shapeshifter. Colour: green
  • Available from the start (unlock level 0)
  • Base stats: 70 HP, 10 damage, a shot every 0.4 s, move speed 190
  • Passive: Antigenic Drift changes your shot type every 4 s (Standard, Piercing, Splitting, Explosive)
  • Signature (SHIFT): Antigenic Shift, a ring of 16 mixed bolts plus 8 s of double fire rate
  • Ultimate: Pandemic, a 300-radius wave that hits for 40 and infects every cell in reach
  • The only virus whose shots change colour with its shot type
  • Has no organ milestone bonuses
Compare the playable viruses
Influenza A in the Bloodstream
Influenza A in the Bloodstream
On this page8
  1. Antigenic Drift
  2. Standard Shot
  3. Piercing Shot
  4. Splitting Shot
  5. Explosive Shot
  6. Antigenic Shift
  7. Pandemic
  8. Influenza A Lab branch

Every 4 seconds your shot type mutates into one of the other three types at random.

  • Cycles between Standard, Piercing, Splitting and Explosive, never repeating the current type
  • The HUD shows DRIFT and the current type, in that type's colour
  • The Rapid Drift Lab upgrade makes shots mutate 0.4 s sooner per level
  • Switching types helps against memory B cells, which take half damage from the last shot type that hit them, and against the immune system learning to resist one shot type
From the Codex

Small mutations that gradually change a virus's surface proteins so antibodies recognise it less well.

Fun fact: This is why the flu vaccine is updated almost every year.

Antigenic Drift in the Codex

Standard Shot

Shot type

A plain green shot.

  • Colour: green
  • The type every run starts with
From the Codex

Your virus fires on its own at the nearest cell it can see.

Fun fact: Positioning is your aim: stand where the cell you want is the nearest one in sight.

Auto-Attack & Shot Types in the Codex

Piercing Shot

Shot type

A blue shot that passes through cells.

  • Passes through 2 extra cells
  • Neuraminidase Cleave (Lab) adds +1 pierce per level
  • Colour: blue
From the Codex

Your virus fires on its own at the nearest cell it can see.

Fun fact: Positioning is your aim: stand where the cell you want is the nearest one in sight.

Auto-Attack & Shot Types in the Codex

A yellow shot that splits in two when it hits.

  • On a hit, two half-damage shards fly off at an angle on either side
  • Shards don't split again
  • Colour: yellow
From the Codex

Your virus fires on its own at the nearest cell it can see.

Fun fact: Positioning is your aim: stand where the cell you want is the nearest one in sight.

Auto-Attack & Shot Types in the Codex

A bigger red shot that bursts on impact and cracks armor.

  • Bursts in a 70 radius for 50% of the shot's damage to other cells
  • Explosive damage breaks armor 1.6x faster (good against Adenovirus and armored elites)
  • Colour: red
From the Codex

Your virus fires on its own at the nearest cell it can see.

Fun fact: Positioning is your aim: stand where the cell you want is the nearest one in sight.

Auto-Attack & Shot Types in the Codex

Antigenic Shift

Signature · SHIFT

Fires a ring of every mutation at once, then 8 seconds of rapid fire with random shot types.

  • Fires 16 bolts in a full circle, cycling through all four shot types, each at 150% damage
  • For 8 s your fire rate doubles and every shot is a random type (HUD: SHIFT · MIXED)
  • It's loud: Detection +8
  • Reassortment Burst (Lab) adds +4 bolts per level
From the Codex

An abrupt, major change in a flu virus, caused when two strains infect the same cell and swap RNA segments (reassortment).

Fun fact: Shifts have produced new pandemic strains, including those of 1957, 1968 and 2009.

Antigenic Shift in the Codex

Pandemic

Ultimate

A viral wave that damages and infects every cell nearby.

  • Hits every cell within 300 for 40 damage
  • Infects survivors: they glow green and burn for 6 damage per second for 5 s
  • Lingering Fever (Lab): infection lasts +2 s and burns +3/s per level
  • The Superspreader Lab upgrade makes infected cells pass the infection to cells within 130 when they die (from the Liver on, each cell shrugs it off 25% of the time)
From the Codex

Each infected cell releases new virions that go on to infect its neighbours, so an infection can grow exponentially.

Fun fact: A single flu-infected cell can release thousands of new virions within hours.

Viral Spread in the Codex

Influenza A's own Petri Lab upgrades for its signature ability and ultimate.

  • Rapid Drift (4 levels): shots mutate 0.4 s sooner per level
  • Reassortment Burst (3 levels): Antigenic Shift fires +4 bolts per level
  • Neuraminidase Cleave (2 levels, 1 RNA to unlock): piercing shots pass through +1 more cell per level
  • Pandemic Reach (3 levels): wave radius +20% per level
  • Viral Shedding (3 levels): ultimate charges 15% faster per level
  • Lingering Fever (2 levels, 2 RNA): infection lasts +2 s and burns +3/s per level
  • Superspreader (1 level, 3 RNA): infected cells pass the infection on when they die
From the Codex

Permanent upgrades. The core ones are shared by every virus; ability and ultimate ones belong to one virus.

Fun fact: Pick an upgrade to see every level and milestone.

Petri Lab in the Codex

See also