In the end it's just more of the breakdown of the trans-atlantic cooperative model that kept western (and especially the Anglo/American countries) economies relatively integrated for the last few decades and which broke down significantly after the election of Trump.

This has been especially difficult for us in Canada where our dependant relationship with the US ("sleeping with an elephant") has screwed us not just on vaccine supply but on other geopolitical issues (China imprisoning our citizens as proxy conflict with the US, trade conflict over steel and aluminum and dairy, etc.).

If you traveled back 15-20 years and told people at the time that there would be a situation where Canada would be poor in vaccine supply while the US was drowning in it, people would be a bit shocked. During the Clinton/Chretien era this kind of lack of cooperation would be unheard of, continental integration was the agenda of the day.

Some of this is now alleviating with Biden at the helm, but it's still not a good situation. We just "borrowed" 1.5M doses of AstraZeneca from the US that they weren't using, but that's really a drop in the bucket.

So yeah, it's not just EU vs UK, it's a whole situation, the breakdown of the neo-liberal concensus. It's not clear what replaces it.