Sorry, what did I say that wasn't 'remotely true'? The various international, privately or publically (but neither nationalised nor 'supranationalised') owned drugs companies that develop, produce and sell the vaccines happen to have their European production and distribution centres in EU member countries. This does not make them, or the vaccines that they produce, a possession of the EU. The exports that are made by these companies, be it to Mexico, Canada, the US or even the UK are a matter of contract between the companies and the countries concerned. Unfortunately for the citizens of the EU countries, the Commission, the member countries and the EMA were all caught picking their noses, scratching their backsides, dreamily perusing lengthy legal texts or doodling tasteful pictures of blue starry flags when they should have been getting their own contracts in place and the vaccines cleared for use. It is not the fault of Mexico, Canada, the US or the UK that they weren't.
The piece that you have quoted, as interesting as it may be, is entirely irrelevant to this pretty straightforward fact. The piece clearly has an axe to grind regarding the UK, which obviously accords with your own anti-UK sensibilities. The above notwithstanding, I notice that it also fails to mention two or three things that spring to mind. The Halix plant which is 'strongly suspected' to have sent 'non-trivial' amounts of the AZ vaccine to the UK was apparently set up with £24bn of UK taxpayers' money, and was contracted early by the UK government to supply...the UK, that the 'pragmatic' and 'ethical' decision by EU member states to outsource the acquisition and rollout of the vaccines to the EC has been a spectacular failure, not helped at all by the toxic anti UK/AZ narrative which has been triggered and perpetuated by one or two notable EU member state leaders and EC functionaries, and that a 'degree of solidarity' didn't preclude Germany from nipping out of the back door to secure an extra 30 million doses for itself.