Looking at the big world powers testing the vaccines first, being able to afford it most, and basically have the economy to close shop and wait for it to pass most.

I would have to say that nothing would make a world power go down as much as you think it would. Sure Europe will get vaccine from UK a lot later, probably politics related stuff but it is still Europe getting it and not central Africa, you think they do not have any corona virus cases? They probably do not have a way of testing it while others are already moving to vaccination period. So long story short world powers will never give up their seats and they are willing to use politics to hurt other nations and let their people die just to prove to their people that they are the strongest in the world.