These communities are more than "anti-vaxx." Likely the vaccination rate in most of Canada is sufficient to make R0 < 1, but in these communities that eschew modern anything and have a near-zero vaccination rate, it's now endemic.
The "immigrants" that spread this one were Ontarians visiting New Brunswick and bringing it back to Ontario. Do you want vaccine passports at provincial borders now?
https://www.ctvnews.ca/toronto/article/measles-outbreak-trac...
Here's a case where a Mennonite kid who brought it home after catching it from an unvaccinated 9-year-old from the UK while on a trip to Disneyland (see p 251). Are you blaming that on "immigrants"? TBH - your comment presents as nothing more than lazy racism.
https://www.canada.ca/content/dam/phac-aspc/migration/phac-a...
The Anabaptist communities are well aware that they are at special risk when the whole community opts-out. What's changed is they are starting to travel and build a truly international community. Once you combine international travel and a vaccine-hesitant community, you're going to have trouble. Immigrants have nothing to do with this.
https://www.mennoniteusa.org/measles/
2002 - https://www.immunize.ca/sites/default/files/resources/74e.pd... 2015 - https://www.cbc.ca/news/canada/calgary/immunization-rates-so... 2025 - https://www.ctvnews.ca/toronto/article/measles-outbreak-trac...