They're into folk medicine, but their anti-vax issues generally come from people who don't have any means of knowing better (i.e. never been to school, dropped out at a very early grade, isolated, not even literate). Typically just education and having a doctor or a local elder respectfully explain to them that the Polio shot will help prevent their child from being paralyzed for life is enough to convince them.

Meanwhile the 'educated' Westerner, to whom Polio is a third-world disease, will convince themselves that the doctor is lying for some reason, will choose to take the 75% chance of an asymptomatic infection because they don't truly appreciate how bad it can otherwise be, will use their access to a vast collection of humanity's information to cherry pick data that supports their position (most likely while also claiming to seek debate despite not intending to seriously consider opposing evidence), and if their gamble fails, will probably just blame immigrants, government or 'big pharma' for doing it.