Of course. As I said in my other comment, there is a lot of politics involved, not least because of Brexit and, frankly because the EU did not do very well (they may be looking for a diversion...) here while the UK did.
EU diversified their vaccine contracts, negotiated fair prices, generously funded the manufacturing rollout, avoided vaccine nationalism between member states, equitably distributed the vaccines amongst their members and the key point - holds the manufacturers liable for possible damages.
All of those points are entirely reasonable. One could argue that EU should have paid more, but there are two counterarguments: Firstly, it doesn't really move a needle, as both US and UK have home-front-first clauses, leaving only Israel and Arab oil producers skipping the queue. Secondly, said countries could just amend their contracts, bid up the price, and everyone is back at square one.
Date of contract signing doesn't really matter either - a credible commitment to massive orders has been there from the very beginning.
European Medical Agency gets a lot of undeserved flak for being slow and bureaucratic. Pfizer was approved mere 10 days later than in the US, Moderna got approved earlier than in the UK, and now AstraZeneca earlier than in the US. Allegedly, even those slippages were caused by the companies simply prioritizing their US/UK approvals.
Partially, EU got unlucky - Sanofi vaccine flopped, AZ plant has technical problems, Curevac got delayed. In a world where Pfizer and AZ wouldn't underdeliver by an order of magnitude, EU plan would be praised and touted as a gold standard. Partially, EU was always fighting an uphill battle - the corporations that cleared the approvals simply care more about their image in the US/UK, don't like to face competent regulators, and really dislike being liable. Afaik, they face no liability in US and Israel.
That being said, absent the EU policy, I'm quite confident that small countries like Latvia, Slovenia or Finland would end up with the short end of the stick.
That would be "doing very well"?
Because it seems that's what UK is doing with AZ, their production stays in the UK. And that's doing well?
If so, then EU should most definitely lock out exports of vaccines.
Sanofi announced a couple of days ago that they're at the disposal of BioNTech for vaccine production.
I'll give my answer: Because it would have been a catastrophe for many countries that depend on these vaccines - especially those that are now doing quite well. Israel, Canada and so on.
I personally find what the UK did ethically wrong. As it stands, there'll be no recourse for the EU that isn't as bad or arguably even worse.
British people patting their own back about the ingenuity of mandating exclusive contracts for UK facilities - which factually is the same as export controls - is in my eyes quite detestable.
The EU did everything wrong they could do wrong. But at the very least, they don't mandate an "EU first" clause.