Children don't necessarily need to be taken away, but they do need to be vaccinated no matter what they're parents think. In the mean time if their child dies or they infect someone else and they die they should then have their kids taken away and be prosecuted for murder.
How on earth does that logic work?
Not vaccinating against say measles, is taking a chance that a child will contract a disease that has a chance of killing them. Is it a dumb thing to do? Yes. Is it tragic when the ? Yes. Does it come remotely close to what the legal system defines murder as? No!
We don't even charge drunk drivers who kill people with murder. They get manslaughter, and they take a heck of a lot more risk than an anti-vaxxer does.