I would assume that the countries are the only ones with a factory that is capable of making this. Give me a few billion dollars and a year and I can set up another factory, but it would have been too risky an investment 1 year ago (before COVID), or even 3 months ago . Even now it is too risky an investment as the current factories can produce a lot of vaccine, and there are other candidates that also have factories, so odds are the world will be vaccinated before my 1 year factory comes online.

A 1 year factory build is extremely fast - freely trading money for time. A more reasonable schedule would be several years (a lot cheaper)

Didn't Bill Gates' foundation invest 6-7 billion dollars in manufactoring capabilities for vaccines this spring?

I think he cares about cost effective. He is expecting more than a year to get them running, but in return he can get far more vaccine. He has been working for years on getting various vaccines and has a good idea what the long game is by now.