Both approved vaccines in the US require a followup shot about 4 weeks later. Somewhere I read that Operation Warpspeed is holding back 55% of the vaccines to allow for this. (They had a reason for holding back more than 50%, but I forget what it was.) Then I read about one or two states that were holding back half of what they received for the same reason. Likely this is happening in more than the ones I read about. And I thought I read (perhaps on this board) about a hospital doing the same.
So with all that holding back, there may be only about 10% of the doses actually getting to people. No wonder they’re so far behind what they planned to inject by now.
I think the 55% is to allow for a small amount to be rendered unusable through not being used up soon enough after being opened, or accidentally being allowed to get too warm. The stuff has to be kept really cold, so some kind of failure, whether human error, or mechanical or electric, is pretty likely to affect a few vials at some point.
It sure seems like the problem isn’t one of supply, it’s one of logistics. They have far more vaccine than they’re capable of sticking into people’s arms. My neighbor owns an independent pharmacy and blames it on the CVS/Walgreens distribution plan.