The cost of a dangerous vaccine could be one hundred years of lower uptake of ALL vaccines decimating the populations of nearly every country in the world. Not worth the risk if you ask me.
I'm not sure a small subset having a bad reaction to a known-untested vaccine they volunteered to have would have quite as bad an impact as you say, certainly not 100 years of lower uptake!
It would likely have some kind of an impact though, and give fuel to anti-vaxxer types (yuk) but I am not sure the impact would be quite so severe.