Hand Sanitizer
Hand Sanitizer
[Cueball looks at a poster while holding a bottle.] Poster: An invisible sneeze droplet can contain 200 million germs!
[Same scene, except Cueball is looking at the bottle.] Product label: Our hand sanitizer kills 99.99% of germs!
[Cueball types on a calculator while still holding the product.] Cueball (typing on calculator): 200 000 000 × 0.01% =
[Cueball holds down his calculator.] Cueball: Ew.

The number of germs that would be left after using the hand sanitizer is 200 million times 0.01%. 0.01% is equivalent to 0.0001 in decimal, so the multiplication is 200 000 000 × 0.0001. That is 20 thousand germs, which is still a surprisingly large number of germs. Recently, scientists have shown that it only takes 20 virus particles to infect someone (with analyzed virus; not all germs are equally effective). However, they have also previously noted that the effectiveness of hand sanitizer is actually higher than 99.99%, but it's a bit awkward to print a more precise decimal in an advertising slogan. (Several brands actually kill near 100%, but don't want to risk going to court for false advertising because a few germs got past.)
"Hipster CDC" is a combination of the acronym for the Centers for Disease Control and Prevention , an organization dedicated to studying infectious diseases and limiting their spread, with the label hipster . Hipsters form a cultural group associated with a distaste for popular culture; they stereotypically talk about how bands, authors, etc. were better before they "went mainstream" and proclaim that they liked a certain thing "before it was cool."
The title text extends this sensibility to the flu, which in fact did peak years ago, such as in 1918, when a world-wide flu epidemic killed tens of millions. The humor lies in the notion that the "Hipster CDC" apparently approves of the time when the flu was more widespread and fatal, while most people consider the diminishment of the flu is a good thing. This could be a jab at hipsters' common insistence on liking things before they "go mainstream": many things, before they go mainstream, just aren't very good, and therefore hipsters' taste in things is highly questionable.
[Cueball looks at a poster while holding a bottle.] Poster: An invisible sneeze droplet can contain 200 million germs!
[Same scene, except Cueball is looking at the bottle.] Product label: Our hand sanitizer kills 99.99% of germs!
[Cueball types on a calculator while still holding the product.] Cueball (typing on calculator): 200 000 000 × 0.01% =
[Cueball holds down his calculator.] Cueball: Ew.
