I'm not so sure. Part of their vaccine-free lifestyle involves a serious disregard for the health and well-being of others. Polio does not make everyone seriously ill--only about 1 in 200. Unless their kid is that one in 200 who actually becomes disabled from polio, they won't care. We've already seen this where whooping cough outbreaks have occurred in strongly anti-vax areas--these people don't even care about protecting their own children, much less other people's children.
It was not due to anti-vaccine locally, but to a wrinkle in the protocol for adults. I always get my tetanus on time because I work with dogs and horses. Adults get combination pertussis-diphtheria-tetanus shot, but the tetanus is a 10-year and the pertussis only lasts 4-5 in some cases.
Fortunately it's not life threatening in adults, and I didn't pass it on to any of my coworkers' kids.