The mRNA vaccines also had a cloth problem (as in, it was extremely rare), that practically disappeared with a change on the application procedure.

Can you elaborate? What was the change?

	▲	atomicnumber3 2 hours ago \| parent [-]
		I am quite curious too. I had heard that, despite arm vascular being very consistent among individuals, it does still vary. And I think for most vaccines I guess it doesn't matter if you hit something other than muscle. Maybe for the mRNA vaccines it does matter? I'm baselessly speculating though. Wish other person hadn't been so vague.