I don't think they even give polio vaccines in the first world now. They've almost got it eradicated except for a few places in such as Africa, but they say it's making a comeback because they won't use the most effective medicines (more expensive and harder to use) to vaccinate people. There's a difference of like 19% efficiency though.

I read a bunch of stuff about polio the other day and it was so depressing and kinda scary really. My mom has a huge scar on her arm from when she got vaccinated when she was like 4 or 5.