Europe's COVID-19 vaccine rollout with AstraZeneca Plc (NASDAQ: AZN ) has intensified further, with at least nine countries suspending the use of the shot over safety concerns, reports Bloomberg. This latest concern comes on top of the company's already existing supply problem with the EU. What Happened: Austria was the first to raise concerns. Denmark, Italy, and Norway soon jumped the bandwagon, pointing to instances of blood clotting that health authorities want to investigate more closely. Although last week, Italy stopped around 250,000 doses of the vaccine from its Anagni, Italy, plant being shipped to Australia.