Here's a thread that lays out the actual facts around this.
Thanks for this, interesting read. He did say "It seems like..." which I wondered is it fact or assumption. Briefly read through it and I disagree with the following:
Meanwhile EU has exported 10m (mostly Pfizer) doses to UK, while 'UK 1st' clause stops AZ from meeting EU delivery promise from UK plants.
As for as I know, the UK signed contracts with Pfizer and AZ, not the EU. The fact that the vaccines were manufactured in a country that is a member state of EU doesn't mean the EU exported it, the company manufacturing the vaccines exported it.
Once everything went pear shaped for EU, they try to force AZ and UK into giving vaccines made in UK to EU, and then imposed the rules that the EU are the only ones that can authorize an EU country to export vaccines outside the EU, basically forcing private companies to breach on contracts, not because of their own doing, but the EU wanting the vaccines for its own vaccine program. Of course, this was a major mistake that criticised world wide and they backtracked, and even admitted the mistake a few weeks later.
At the end of the day, the EU is not manufacturing nor exporting these vaccines, private international companies are. The UK was invited to join the EU's vaccine rollout program in 2020, but declined and decided to go it alone. The EU thought the UK would then act as a good old neighbour (1st country) and share, but why would the UK when it was the EU saying "Brexit is Brexit" and "UK is a 3rd country" every week.
But for me, this is the kicker in how the EU believes they should be treated differently and with higher regard than UK. They wanted all plants in EU and UK to provide vaccines to EU program to make up the shortfall, which is a clause in their contract with AZ. BUT, the UK has "1st clause" because they signed up first and negotiated, and the EU ended up the the "best effort" clause with no guarantee of dosages . Why should the EU believe AZ should now break a legal contract with UK so that the EU can hold up it's contract, ignore the "best effort" clause (which they initially did), and then say the only clause that matters is the one about all EU plants including UK will provide vaccines to EU. I do wonder if the EU had not done their usual demanding and telling and actually approached the UK and AZ in a friendly manner what the outcome would have been.