>Just a reminder it was the US that blocked vaccine exports.
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, 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.
By early June 2020 (<https://web.archive.org/web/20200603171013/https://www.nytim...>) the Trump administration had already identified and was planning to sign the aforementioned huge contracts with Moderna, AstraZeneca, J&J, Merck, and Pfizer. (An 80% success rate is fantastic in drug discovery.) By that time the US had already paid $2.2 billion to three of the companies. (Also note the skepticism throughout that any vaccines could be delivered anywhere within the timeframe the administration was promising.)
The UK signed a similar contract for the AstraZeneca vaccine. The EU and Canada did not assure themselves of such quantities. Canada also bet on CanSino 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 in addition to the non-UK doses it bought.
(I don't disagree that to country B waiting on doses, the outcome is the same whether or not the cause is country A implementing an export ban or country A having bought up all the doses by having signed the contract first. But there is a difference.)
If the situation were different, might the US have implemented a ban on exports, similar to what the EU did implement toward Australia? 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.
>While we in the EU let the free market handle things.
Except Italy as I mentioned, blocking export of vaccine to Australia that the latter had paid for. More to the point, the EU did not ban vaccine exports more widely because it was afraid that the US would cut off component supply chains.
>Of course, EU countries were smart enough to buy vaccines collectively :)
... and because the aforementioned collective effort was delayed relative to the US and UK, the EU saw significant vaccine shortages earlier this year.