Our knockout roses have the incurable virus, I think it's called RRD. We have our bushes sprayed by a lawn care but our neighbors don't have theirs sprayed. If we plant new knockout roses, would they probably get the disease again since neighbors do not spray their bushes to keep them from becoming diseased?
Diseased Knockout Roses
If the neighbors roses do have Rose Rosette Disease then it could spread to your rosebushes. However no spray will prevent RRD as it is a virus and not a fungal or other form of attacker. If the neighbors roses have RRD, it would be best to inform them of it and hopefully they will do the right thing and get rid of them. The new Knockouts should be find if their roses show no signs of the nasty disease. Here is an link to an article for you too: