The AZ study showed 90% effective in one trial. 60% effective in the other.
Overall 70+% effective. But the 90% efficacy was giving half a dose at first, and then a full dose 3 weeks later. The lower figure was for a full dose up front and then another full dose 3 weeks out. They really don't know why the lesser initial dose was much more successful. But if that pans out, it's good news as you use less vaccine so can stretch production further. It also doesn't need any special cooling techniques.
Overall, I don't think the Trump Admin was careful or concerned about gov't spending. With PPE and ventilators it was throw money all around, including to cronies with inexperienced start-ups. I think Trump just looks at gov't money as easy money, ripe to be plucked. And I think the vaccine contracts will reflect that lax and perhaps even fraudulent standard. Biden's team needs to audit all the contracts and rescind any garbage contracts to useless cronies. look for fraud throughout the year because it's in there.