What I’d expect to see to scale up getting needles in arms (off the top of my head):
All major population centers with multiple vaccination centers (temporary tents, school gyms, etc)
Should go without saying that these places should be very strict about masks, distancing, ventilation, etc.
Drop-in vaccinations allowed, forcing appointments shouldn’t be a high priority
but make it easy to see delays
delays mean you probably don’t have enough vaccination centers
quickly built appointment and tracking systems will themselves fail enough to slow down vaccinations; keep it simple and low-tech
Don’t worry so much about “fairness”
the goal is to get needles in arms, as quickly as possible (it doesn’t much matter that the most vulnerable don’t strictly come first if you’re quickly vaccinating the majority of people)
handle vulnerable or non-mobile populations separately, by bringing the vaccine to them
cheaters (people jumping the queue) don’t matter that much if you’re vaccinating many quickly
Don’t worry so much about tracking who’s been vaccinated or not
assume people aren’t so stupid as to get vaccinated multiple times; likely not a major problem
you can’t force people to get vaccinated, so don’t worry about it; make it easy for those that want it
That we’re not seeing these sorts of things (in Canada, where I am) feels like the people making these decisions aren’t really prioritizing vaccinating people. Maybe that’ll change in a couple of months, but we’ve had a long time to prepare for actually having vaccines available, so again feels like a failure to really prioritize (as in “does this thing make it easier or harder to get vaccinated now?”). There are risks (of the “unknown unknown” variety) that can happen just by being so slow (e.g., yet-another-variant that requires yet-another-vaccine)
Of course not having enough vaccine on hand makes things slower, but even then I think vaccinating with as little overhead as possible is preferable, since until the actual case numbers come down, vaccinated or not, people need to be careful, and being vaccinated doesn’t really affect your life much until then.
What I find silly and embarrassing is that with all the time to prepare, we’re still so bad at this (in Canada, but doesn’t seem much better than USA). Israel seems like the country to emulate at the moment. And if you hear about doses expiring, that is pure incompetence: just give it to anyone that wants it at that point.