Here's what I do. I have my kids injected with weakened or dead pathogens. Sometimes I can I can just have them injected with a molecule that looks like a pathogen.
Or giving them Long Covid at some point. There is a chance of getting it with each new infection, much larger when not vaccinated. And each infection can also shave off a few IQ points.
These people also sound like the types to get right into other people's faces at the grocery stores to excitedly tell everyone how healthy they are by not getting vacced.
Rub some butter on their feet and have them carry a wrinkled potato around with them. Guaranteed to keep the flu away. For a cough, it's potatoes on the feet and butter in the hands.
Don't forget to massage in a nice herb rub at bed time, then wrap them in foil before covering them in the electric blanket for 20 minutes at 350° to really seal in the flavor.