Part of the problem is American parents not doing their job of immunizing their kids and then you have the anti vaccine Moms who add to the problem.
The schools here in Oregon had to go start refusing kids due to lack of parental compliance. And they even had free vaccines.
I AM one. I opted out for my children (ages now: 17-28)
As long as you immunize, it is none of your business whether I do or not. (Because you are supposedly safe)
Being a right-wing conspirator, I don't think it is the job of the government (including education system) to tell me what I must do with my body, or that of my children.