I suspect many more doses have been given but not reported (B), and a lot more of the shortfall can be explained by A & C.
If that's true, we're going to be production limited very soon... though the decision to hold back more than half of the doses doesn't help.
Reaching phase 1B will help, too, because it will mean the opening of mass vaccination clinics, which can run in parallel to the remaining portion of 1A which is more targeted and logistically complicated. E.g. Santa Clara County Fairgrounds are set up for high throughput drive-through COVID testing and plans are to use the same infrastructure that can host massive numbers of cars and lanes to have massive numbers vaccinated and waiting out their 20 minute observation time. This site will be able to do thousands of doses per day-- >0.3% of the County's population per day-- alone, which exceeds the number of doses we can be expected to be allocated for quite some time.
Johnson and Johnson is the best hope for another near-term EUA, which could significantly improve vaccine supply in February.
There's no guarantee things would be going any faster, but if anyone can walk into a pharmacy and get a shot it seems like it would speed up a bit.
The Oxford vaccine can be stored in a regular refrigerator, which drastically reduces infrastructure cost and makes it speedier to administer, since it doesn’t need to be carefully warmed to room temperature from subzero.
Oh, and it’s cheaper. That matters.