Good Morning @ninahaskin , good to "see" you again.
I just posted this in reply to another comment on this thread:

As a child, (I was born in 1955) I was given the ORIGINAL SALK POLIO vaccine; an inactivated culture of the virus was injected?
Thing was, they didn't *QUITE* deactivate my sample, and I contracted Polio at age 3 (or less) I was paralyzed on my right side for 2 wks before MY BODY finished the job.
It was said then that I would NEVER NEED another vaccination or booster as I now had natural immunity.
When I went into the military, I had no way of proving this, so I got Polio vaccines.

Why is that procedure not good enough (I was told the virus was killed with xrays or radiation before being injected) today? I like the idea of that much better.