^^ (Intended for PG)
https://www.npr.org/sections/health-...d-out-a-killer
How long had the Polio virus been circulating before a vax was developed? - About 60 years
How widespread was testing? - Don't know
What resistance was there to the vaccine? - Some for the first couple of years, mostly due to a botched batch of vaccine that caused some deaths. It's a dead-virus vaccine and some of the virus in that batch wasn't dead and actually introduced polio to some of the receivers of the vaccine. The problem was identified and fixed. My understanding of this virus is that it's different in that it's a RMA messenger and of a different, and safer, methodology than dead-virus vaccines.
How was that resistance overcome? - By the pictures of crippled and dead children. Polio was/is an insidious disease. My parents, having lived through it with my sister, were highly compelled to get me vaccinated when I could be. The risks of vaccination are very low, compared to the risks of getting the disease. People also tended to be trusting of those who actually were scientists and understood the enemy and how to fight it, not so much armchair epidemiologists who would question things they didn't understand.
Bottom Line: We need to eradicate Covid 19. In order to do that effectively, we need to develop herd immunity. Get the fucking shot.