The problem here is that not all diseases are the same in terms of risk to health/life or even the ability to infect others. Comparing Smallpox to Polio to the

The problem here is that not all diseases are the same in terms of risk to health/life or even the ability to infect others. Comparing Smallpox to Polio to the Measles in equal terms is a stretch at best and probably closer to being dishonest. Many people recognize that either wittingly or unwittingly and so getting vaccinated against Measles and Chicken Pox just isn't a high priority. Now to talk about the MMR vaccine: It has had a rough go the last few decades. It was reformulated a couple decades or so ago and the efficacy was massively reduced to around 30% or less if I remember correctly. They went back to the old formulation later but not after a full decade or more of using the new formula that didn't really work. In several of the measles outbreaks of the last decade or so - most, if not all, of those that got the measles had been vaccinated. Of course then everybody blames the anti-vaxers for the outbreaks :(