One of the challenges the EU often has when negotiating is dealing with the need for consensus among their 27 member states, and trying to reflect so many diverse political desires in negotiations.

While the result is a "civil service" style European Commission, the end result is generally some kind of compromise or "average". It's hard for the EU to conduct a negotiation over vaccines when there's national interests lobbying for bulk buying of French candidate vaccines vs. German-made vaccines etc.

This makes it far harder for them to negotiate anything, unless they can all pre-arrange their own position. As soon as their desires diverge, the negotiation gets much harder for them, as they have to try and negotiate a compromise position that keeps everyone equally unhappy.