While agreeing with your general premise: pertussis is most definitely not extinct, unfortunately. We see recurrent waves of it in California about every five y

While agreeing with your general premise: pertussis is most definitely not extinct, unfortunately. We see recurrent waves of it in California about every five years. The problem is in adults (who haven't had a booster in ages) it's frequently mistaken for a bad cold, but it can kill young children. Also, because of their sheer ability to spread, MMR diseases can be big problems outside of the United States, though they are usually restricted to small pockets in the USA for exactly the reasons you mention. This is why we have to pay attention to community levels of vaccination, not just state or county-level. All outbreaks start local.