Believe it or not AZ has been a problem for many EU countries and they have been caught with their pants down.
The nature of the EU deal is that everyone is entitled to buy an equal share of vaccines depending on their population. Each country had/have many multiples of their populations vaccines bought.
However not all countries ordered the same vaccines. For example many countries decided to buy large quantities of AZ as it was cheaper and declined to take up their full allocation of the more expensive MRNA‘S. These countries having difficulty at the mo are the ones who backed AZ to heavily, not that AZ isn’t a decent vaccine they just bet to heavily on the one horse and the horse can’t meet the demand at the mo. Countries are entitled to buy extra vaccines if they wish, outside their EU collective, if they can, that’s a private matter for the country, Germany and France both have, Ireland have made orders of 8 mill for vaccines for next winter.
The vaccine race is a long one, I’d be cautious at making judgements at the moment on success and failure just yet, probably just the end of the beginning and could be a few important variables that could see the grid change.