Thanks to Andréa, who called it a “CIDU that I’m too lazy to look up.”
I gave in and looked it up! Alicia Keys had a song “Girl on Fire”. And the lookup also finds a few parodies, under titles like “This girl is on Pfizer,” that predate this cartoon. Indeed it seems to be a fast-moving meme, with hashtags on Twitter and TikTok.
The list of manufacturers sounds like the choices for Covid vaccine, though I guess they would be similar for Flu. The song parody with available lyrics certainly made it Covid, and it’s tempting to suppose that was Hilburn’s idea at first which then got softened, as it were. (The actual song dates from 2012)
Comics I Don't Understand 
What’s up with the light bulb over Pfizer Girl’s head?
I think she’s Alicia Keys, having her inspiration.
Thanks for the Alicia Keys explanation.
We love Argyle Sweater daily strips!
Thanks and keep ‘em coming please!😻
Thanks. That explains the different treatment of the “Z”. Without it, we get “pfier” — something like “fire.”
The facial scribble in the lower left corner was an unfortunate distracting detail, making the “inspirational” lightbulb appear like it might be another one of those annoying “Easter egg” hunts. Repeating the name “Johnson” four times didn’t help, either: it proves that the author uses a fake “handwritten” font.
I think that the light bulb shows that the seated woman woman is on Pfizer – not the nurse and that woman is “on fire” with an idea.
I think everyone understood that the nurse wasn’t referring to herself, but the person on the end, apparently Alicia Keys. The bulb is because she heard that and got an idea for a song, “Girl on Fire”, which contains in the chorus the line, “This girl is on fire.”
Yet another “inspiration” joke then.
Like this one:
Beethoven, to his girlfriend: “You’re my inspiration!”
Girlfriend: “Me, your inspiration? Ha Ha Ha HAAAAAAAAA!”