Episode 3

"Influenza" (インフルエンザ) is the third episode of the Cells at Work! anime. It is based on the third chapter of the manga which has the same title.

Synopsis
Naive T Cell is completely terrified and useless for his first patrol. He flees the battleground, leaving Killer T Cells, Neutrophils, and Macrophages on their own.

Plot
Naive T Cell's patrolling an abandoned section of the body when he runs into the Influenza-infected Cells. As he has never partaken in a battle before, he gets Scared and then he's almost killed, but White Blood Cell saves him. Then White Blood Cell fights the Influenza, but he can't make much progress because Naive's too afraid to fight. However, Macrophage arrives and assists White Blood Cell, and then she examines the Influenza, discovering it to be a Type-B virus. Then she contacts Helper T Cell, who sends the T Cell division towards their location.

Then White Blood Cell and Macrophage clear out the remaining Influenza virus. Then Naive asks the two to tell his senpai that he managed a kill, but Killer T Cell and the T Division arrive. Then they immediately know that Naive didn't contribute and start yelling at him before dragging him off to combat the Influenza epidemic. Then the other Neutrophil arrive after the T Division leaves.

In another area of the body, the influenza begins their rampage. Macrophage, the T and Neutrophil division engage the enemies. The T Division gets Naive to fight, but he becomes terrified and drops his weapon, forcing Killer to save him. The division then starts yelling at him again, causing Naive to run off. Elsewhere, normal cells run away, which prompts Red Blood Cell and Senior Red Blood Cell to ask a cell what's going on, to which he informs them of an Influenza epidemic.

Naive runs off to the Dendritic tree where Dendritic Cell asks him what's the problem. He tells him that he's too scared to fight and that his senpais keep yelling him for not contributing to the battle. Dendritic Cell grabs several photo albums, telling Naive to look at them. Naive opens the albums and realizes that the T cells in the album are his senpais when they were younger. Dendritic explains that his senpais were also Naive T cells and that they evolved into the Killer T Cells that they are today, stating that they see a part of themselves in Naive. Back at the battlefield, Killer T and the rest of the division are in mental pain, having sensed someone peeking into their youth.

The Influenza virus continues to multiply and infect more normal cells to bolster its ranks, overwhelming the defenders. As an Influenza tries to charge at the group, a fist breaks through the wall and sends it flying. Then Effector T cell introduces himself as the former Naive and reveals that he has also proliferated, allowing them to battle the influenza. B Cell also arrives with his antibodies, but he's ignored by everyone as they're complimenting Effector.

After a week of nonstop fighting, the influenza epidemic is all but eradicated. Just then, the group spots a lone influenza cell. Effector charges at it, only to be slapped aside and sent flying with ease, reverting back to Naive. B Cell sprays his antibodies on it to no effect, causing them to realize that they have a Type A outbreak on their hands. The weary cells are roped into another fight as B cell runs off to make more antibodies.

New characters

 * Naive T Cell
 * Influenza Virus
 * Memory T Cell
 * Effector T Cell (activated form of Naive T Cell)
 * B Cell

Returning characters

 * U-1146
 * Macrophage
 * Dendritic Cell
 * Helper T Cell
 * Regulatory T Cell
 * Killer T Cell
 * AE3803
 * AA5100
 * Cancer Cell (disguised as a normal cell)