With 100 million people getting vaccinated, and afaik most of them with paper documents, how on earth are they going to go back and register all these people into any kind of system? Assuming they still have their cards, assuming they are legible and not accidentally washed in the laundry, and assuming they are willing and able to get ‘registered’ what are people going to do? Go to the local DMV and stand in line? Should it be reverse priority? E.g. the most productive people go first, and retirees go last?
And what about people that had the virus before there were any tests for it, and thus are immune and need no shots for it?
That’s another category along with folks that can’t get the jab (medical & availability reasons).