Smoother certainly.
But paradoxically the overall situation might well have been worse...fewer vaccine doses might have been available.
Because UK was exiting the EU made it easier for UK to act outside the general EU vaccine program. The UK decided to throw a lot of money into their solo program, placed big orders 3 months before EU joint initiative placed any orders, and paid “over the odds” to help some of the big pharmaceutical companies to develop some of the key vaccines in the first place.
The EU placed orders more slowly and negotiated lower prices.
I think without Brexit and UK’s independent approach some of the key vaccines would have been developed more slowly..certainly the Astra Zeneca.
I think it’s probably a Brexit success (plenty of stuff on other side of balance sheet obviously!). But yes...things would in general be smoother if UK still in EU. But we’re out now, time to move on in a spirit of co-operation.