We don't need to "get through to them" any more than we run advertisement campaigns to convince rapists and murderers to please behave, thank you.
These people are endangering lives of other people, first their children and second everyone else (see "herd immunity"). It's time to stop playing nice. Throw them in jail, vaccinate their kids while they're behind bars, let them go after a week with a heavy fine to pay for all the bullshit.
There's a time for being nice and cooperative and friendly, and there's a time for drawing a line in the sand and shooting everyone who crosses it. Everyone with a child knows that you can't yield all the time. Everyone who's ever been in negotiations knows that the right balance between cooperation and shows of strengths gets you the best results. There's even a program by the UN that educated diplomats that incorporates this simple strategy. And if you want to waste an hour of your time, google "Tit for tat", a simple algorithm that is proven to be the optimal strategy in iterated prisoners dilemma and works exactly this way: Reward cooperation with cooperation, punish betrayl, forgive after you've done that.
These people aren't cooperating. Time to stop cooperating with them.