No, it reduces the likelihood. Just like all those vaccines you mentioned. The big difference being that when MMR, polio, and other vaccines were introduced, public officials actually cared about the public as opposed to merely getting reelected. There was not corporate media out there whose sole purpose was to pit one side against the other so that it benefits them to take a completely irrational position just so they can get more viewers and sell their advertising at a higher rate. The reason we so rarely hear about polio anymore is because such a high percentage of people have the polio vaccine that it has limited the spread to such a degree that it is so rare that it is almost gone. The same was almost true with measles in America, until a group of know nothing, moron housewives in California started listening to other know nothing morons on the Internet and decided that vaccines were a bad thing for one reason or another. So, they stopped getting the MMR and measles started to make a comeback.