Ugh this reminds me of a thing that I've heard from anti-vaxxers before when someone tries to point out to them that vaccinations are to protect everybody: "Well that's why you got your kid vaccinated, so I don't see why I should have to do mine." While completely missing the point that this also protects people who can't get vaccinated due to various health reasons.

I'd be willing to write you a fic if you give me a prompt, since I'm rather bad at top-of-my head sort of stuff.