There is no way that a government can ever make a child put something in their body. But they can do a great deal of things in order to encourage behavior. Making sure that unvaccinated children don't hurt other children is a good plan. They have to set policies that are for the greater good.
Unvaccinated children are a risk to those who are vaccinated but have weak immune systems. I think it's a great idea to exclude them from classrooms because we don't know how they will affect their peers if they fall sick. I think exceptions should be made from children who are unable to receive vaccines due to a medical reason.
Yes, prohibiting unvaccinated children from enrolling in childcare is a good idea in the United States. Unvaccinated children can catch contagious diseases that are preventable by vaccination. This may make younger children and vaccinated children sick. Furthermore, it is more dangerous for the children who have not received vaccination to be around other children.
No, it would not be wise for the U.S. to follow Victoria, Australia's vaccination policy. Forced vaccination would violate many of the American values of self-determination and choice. A parent should have the right to refuse a medical procedure they deem unfit for their child without jeprodizing that child's education.