Sam,
Perhaps i’m wrong but i remember reading that there is no vaccine for scarlet fever but somehow that was eradicated! The procamp is very into showing the graph how all the disease took a nose dive from 1940. What’s interesting is if you look at those same figures from 1900 you see that is already a nose dive. From 1940, it only continues the trend. Google it. It is simply amazing! I have never seen a counter argument to this. I think the reasoning is because of poor sanitation etc…which made all these diseases rampant. As conditions improved, the diseases went away. I remember learning in high school how Jews were persecuted because they were not getting of the plagues (bubonic?) because they would frequent mikvas etc and were generally cleaner than goyim….All of this is a fascinating subject and someone has to research both sides objectively and explain the arguments and counterargument on each and every detail….