Will It Ever Come Back? Polio can come back, like most diseases, but it could never be an outbreak the size of the last one because there is a vaccine. You may wonder how it can come back at all if there is a vaccine and there is an answer to that: people have stopped vaccinated their children. You might have seen something about this on the news because it has been a very debatable topic recently. Vaccinating your kids is very important because, a disease like polio could come back and even though you've been vaccinated, you can still get it.