Well, a good chunk of the US anti-vax movement seems to be ultra-Orthodox Jews: https://www.nytimes.com/2019/05/14/nyregion/measles-vaccine-... Their religous beliefs don't permit them to have unfettered Internet access because it'd expose them to corrupting ideas (like, say, the idea that vaccines are safe).
And yet more than a good chunk of the anti-vax movement worldwide has unfettered Internet access. Ultra-orthodox Jews certainly aren't a factor here in New Zealand.