Looking at the numbers it is clear to see that the disease was almost irradiated before the vaccine was introduced. The vaccine obviously was not the source of the huge decline before the vaccine was invented, obviously right. I guess there could have been someone who stumbled accross a flux capacitor who knows. I would say the improvement in hygiene would be the most obviously correlation we could draw, but even more clear is the fact that the vaccine is not what caused the huge decline in these diseases. I am also adding the graph the cdc uses so you can see how they manipulate the numbers.
Also here are a few other diseases that were on a huge decline before the vaccine became available
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