I have a neigbor who has cats who haven't been vaccinated, What can I do?

There's not much you can do. You can't force your neighbors to vaccinate their cats and/or kittens, nor can you get them to spay them. If your cat is vaccinated, then it should be fine from anything these other cats could possibly catch, and as for your child, he or she should be safe likewise. If you're so worried you can ask your neighbors why they haven't yet, and possibly ask them to do it and explain it's for peace of mind, but if they don't you can't do much else. Good luck.