> since [1988] the number of annual [Polio] cases has dropped by 99.9%, from 350/year to a handful

And what's more, that's not even the impressive part of the curve in terms of magnitude. Polio was once so commonplace that the idea of being anti-vax would have been completely absurd to everyone just some 40/50 years ago, when you had someone crippled by childhood paralysis (of which Polio is the most common cause) living in basically every city block. And even in the White House, from 1933 to 1945.