> I took an American one.
Me, too.
> They're safe enough.
How did I know that? Because, the EU and the US work closely together and the regulations make sure that they work with common standard levels.
Each country has a system which regulates which vaccines it considers safe. In EU this is expanded such that the permissions are valid for the common market. The EU has EXPANDED the region where vaccines are permitted under a common regulation, it has not reduced it. Just the opposite.
> Why shouldn't people in China be able to use European vaccines?
For example because China wants to reduce the influence of other countries? Because it wants to promote their own companies? Because foreign vaccines are too expensive?
> If a billion Chinese can use something without it being a problem
How do you know that it does not cause problems for you? Currently it looks like China has a problem with Vaccines.
> We're all the same species and have mostly the same problems.
That sounds silly. Governments, regulators, companies, ... all have different policies, interests, etc. That creates a lot of DIFFERENT problems.
> need a foreign union to negotiate to let me use foreign goods. My own government could
The EU is not a foreign union. It the Union I'm living in. Just like my city, my state, my country, the EU all have different responsibilities. Why should my country dictate laws to my city? It does. Because we are all the same species and have mostly the same problems. In my state, my country, the EU. Those all have negotiated the levels of power they are responsible for.