But there are self-interested reasons to give away vaccines as well. For one thing, there is a non-trivial amount of economic activity that depends on interactions between all nations. Raw materials production, manufacturing, tourism, and so on — all these are greatly enabled by people being able to travel freely between countries. The global economy is thoroughly interdependent, and the more countries that can be certified as virus-free, the more the economy can return to normal.
Now, poor countries are often victimized by trade, and as I have written before, the global economy could badly stand to be reformed to help the working classes of all nations. But until that happens, my point here is that even on the most self-interested grounds, there is every reason for the rich world to pay for universal vaccination.
More importantly, getting the spread of coronavirus down as far as possible — ideally eradicating it altogether — would be a great benefit for all the nations of the world. It’s not clear yet how long vaccine immunity lasts, whether people will need booster shots, and so forth. The fewer chances there are of the virus breaking out and igniting more spread, the better.