Thanks to your helps, and others', I'm getting my first dose today. I've been trying to find answers to the same question you asked in this post.
2 things I'd like answers to are 1) if you had the smallpox vax as a kid, do you have good protection against MP? and 2) Is there any boost from having a childhood smallpox and now one dose for MP?
From my reading, I've seen everything from "they don't know how much protection is left from smallpox vax" to "you'll be covered until you hit 88, if you live that long". Ugh.