Polio is a fecal-oral transmission virus that had already evolved tp survive and attack through the gut. The liquid vaccine on the cubes was a weakened virus vaccinhe.
They swtched to the injectable because the weakened virus sometimes mutated while passing through the gut and caused outbreaks. The injectable is killed virus.
My dad was a polio survivor and we got vaxxed six ways from Sunday as kids.
It seems like in the 50’s, we also got the injections, so why the sugar cubes? I just can’t remember. Your dad had to be a fighter and a good father to make certain his kids were protected. A frightening time for all. Thank you, Valpal1.
You'd think that would have been *required*...