The basic argument of the anti-abortion movement is that the right to life is more important than the right to choose.
I agree with that argument. My freedom of choice ends where the threat to your life begins.
My disagreement with the anti-abortion movement is over when human life begins. I agree with the older Christian philosophy which Dante expressed in the Divine Comedy, that conception creates a vegetable soul, capable of growth, which develops into an animal soul, capable of movement, and only later becomes a human soul, capable of understanding.
Be that as it may, it seems to me that anyone committed to the right to life philosophy would deny that there is a right of parents to withhold vaccination or life-saving medical treatment from children.
The right of the child to live is more important than the right of the parent to choose. And in this case, there is no question as to what constitutes a human life.