They are already testing coronavirus vaccines on humans, including in the US.
I believe it's still going to be the best part of a year away, if following normal approval rules. However, considering the risk of NOT having a vaccine is higher than normal, presumably the approval rules may be adjusted.
I've not read anything suggesting a vaccine should be more expensive than a flu vaccine.
As for treating the whole world, I guess the usual rich nations will get it and the others will depend on aid. [That's how I think it WILL be, not how I think it SHOULD be]
Also, rumour has it that Trump wanted a vaccine "only for the US", so his objective is clear. As he's an obvious danger to the entire planet, I'm really disappointed that
his COVID test was OK.
https://www.dw.com/en/germany-and-us-wr ... a-52777990