This is like a never ending game of cat and mouse. For every anti-vax "fact" that gets refuted, they jump on another anti-vax fact that subsequently gets refuted, and this rinses and repeats until they get back to a previous fact that they forgot was already refuted and addressed.
This rinses and repeats for eternity.
Not only are you nutcases intellectually incompetent, but you also have the memory of a fucking walnut.
I guess this is what it's like trying to fight an STD that just doesn't want to go away.