In the London outbreak of 1900, the mortality among the unvaccinated was 30%
Those who had been vaccinated as infants - once - had dramatically reduced mortality, even those over age 50.
I think the highest mortality for those vaccinated as infants was the 50-60 year old group, and it was under 5%.
Furthermore, it reduces the severity significantly, no going blind, minor scaring, minor organ damage, and then you are immune for life.