>The EU exported over 200 million doses. If the EU wanted, they could've issued an export ban like the US did.
Please stop repeating this lie. There is and has never been a US vaccine export ban, and the US has not seized vaccines meant for other countries.
The Trump administration last year signed gigantic contracts for every planned vaccine (Operation Warp Speed), because no one knew which ones would work. Like, enough for every American from one manufacturer, let alone the current four major available ones. More importantly, the contracts guaranteed the US the earliest deliveries.
The UK signed a similar contract for the AstraZeneca vaccine. The EU and Canada did not assure themselves of such quantities; as RcouF1uZ4gsC said, the former wasted time by trying to get a better price. Canada also bet on CanSino, a Chinese vaccine, because it was afraid that the US would ban vaccine exports (which, again, never happened). Of course, the Chinese did not live up to the contract.
Before you say "But what about—", the Trump executive order from December 2020 merely sets up the legal framework to prohibit exports if desired. But that does not mean that the framework is invoked. Let me repeat: The US signed contracts that were a) huge in size/scope and b) from every pharmaceutical company working on a vaccine, which c) got the country the largest and among the first deliveries. The UK did the same thing with the AstraZeneca vaccine, and spent a lot of money to retool domestic plants to produce it.
If the situation were different, might the US have implemented a ban on exports, similar to what the EU did implement recently? Perhaps. But, fortunately, the US never faced this issue, because of the huge amounts of money it invested a year ago and the contracts it signed with said money.