As announced by the Danish health authority

The rollout and use of the AstraZeneca vaccine is halted temporarily in the country amid concerns that it is leading to increased risks of blood clots.

This relates to the case review posted by the EMA yesterday, in which an Austrian national was diagnosed with multiple thrombosis after receiving the AstraZeneca vaccine.

Keep an eye on this in case more countries start to join in the fray, as we are already seeing Austria, Estonia, Luxembourg, Lithuania, and Latvia temporarily suspend the use of the AstraZeneca vaccine for the time being.

So far, this looks more to threaten the vaccine rollout progress in Europe as there doesn't seem to be much concern about this in the UK. But keep this in view.