As I've just learnt a person needs two injections over two weeks, so double the problems I listed. The flu vaccine is produced in single injection potions which will not be possible for the new vaccine because it's way easier to produce it in bigger pots and it's not known yet how complicated the chilling will be, e.g. a lot of vaccines need -70° chilling, a normal fridge could probably not be enough. I would share your optimism but if I remember how complicated it was to produce and spread a plain product like masks last spring I just can't be so optimistic with the vaccinate process. But hey, let's hope I'm just wrong with my thoughts.