It's fine to take off work if you're sick.
Felicity is not feeling well, but she feels she has to go to work.
Felicity wants to make sure that the report she was working on gets finished.
Felicity calls her boss to tell him she won't be in because she's sick and asks if someone can finish her report.
Felicity goes to work sick to finish working on her report.
Her boss tells her that won't be a problem and that he hopes she feels better.
Felicity spreads her illness to other coworkers, and then they get sick.