"My friend's an irresponsible idiot. What should I do?"

[SteveH]

Killing her is unfortunately illegal, so maybe just end the friendship.
https://www.theguardian.com/lifeandstyle/2021/mar/26/my-friend-is-an-anti-vaxxer-and-shes-converting-my-husband-what-can-i-do

[Roses]

Anti-vaxxers are irresponsible idiots that is for sure. I have come across quite a number of them on various forums, particularly the forums for over 50s. The garbage they spout is dangerous if they persuade people to see it their way.

[SteveH]

I make a point of never calling them "anti-vaxxers", because that's what they want to be called. They think giving themselves a quirkily-spelled abbreviation normalises them, so I call them "anti-vaccinators" (or something ruder). (This is not a criticism of you for calling them that.)