Valid points.
But some countries that are near to China might not think twice in these times. They'll desperately want to get rid of it and if it's the actual vaccine that helped them to overcome the virus, they might give it a try.
I've heard about Russia and Australia too experimenting for the possible vaccine.
every country is looking for vaccine because they all know that they can also be infected not only those big country. The problem about the vacine is it takes a year before they can realease it to the public many testing needed so it will not harm people when its ready and they need to check side effect if they make one.