Replying to Parents not vaccinating their kids

My girlfriend (studying genetics) brought it to my attention that some parents are now trying to prevent the vaccination of their babies/kids. I was under the impression that everyone got vaccinated as a standard procedure, whether you wanted to or not. Apparently, people have a choice. I don't have any papers and I haven't read any articles (although a quick Google search of "not vaccinating your child" brings up plenty of responses, none of which look official or reputable and all of which feel strongly one way or the other).

I'm wondering what NS thinks: should parents be required (by law, the government, etc) to vaccinate their children for the common communicable diseases for which we have vaccines? Keep in mind kids go to daycare/school/playgrounds with other kids, go to the same hospitals you do, and shop at the same grocery stores and Walmarts that you do.

I currently have my own stance, but I'll withhold that for now in the interest of discussion.