This is where some "spin" comes into play, though-- a healthy child, vaccinated for CP, will not expose others simply because s/he was vaccinated, but there IS a risk of contracting CP him/herself from the vax. And IF CP is contracted from having been vaxed, it IS contagious to the rest of the community at large. My 2nd round with CP happened in PRECISELY this manner. Daycare kids were vaxed a week or two before entering my care, caught CP on literally the
2nd day I watched them. I wasn't upset; on the contrary I was glad for the opportunity to expose the two of my children who hadn't had them yet. (Although it turned out that three of mine caught it; one who'd had a very mild case as an infant caught it for a 2nd time.)
BTW, whoever mentioned the incubation period as 9-14 days, just wanted to add that there are always exceptions.
My kids came down with it after about... 5 or maybe 6 days, tops. The daycare kids came to me on a Tue., had CP on Wed., and my kids were breaking out in spots by.... actually I think that very weekend. I ended up caring for FIVE with pox, and everyone who didn't have pox, had a nasty stomach virus on top of everything else. The pox kids eventually caught the virus as well. The whole episode was very un-fun, as my hubby had also JUST deployed the day before I started watching these two harbingers of plague. :
Wouldn't you know!!