This article was originally published by Tyler Durden at ZeroHedge.

Europe’s much-criticized vaccination rollout has just hit another snag, as Danish health authorities are increasingly concerned about harmful side-effects believed to be associated with the AstraZeneca-Oxford jab, the cheap COVID remedy that was supposed to help Europe catch up with the US, UK, and Israel.

Danish authorities on Thursday temporarily suspended AstraZeneca’s COVID-19 shot following reports of cases of dangerous blood clots forming inside patients, including one such incident that took place in Denmark. Authorities didn’t specify exactly how many reports of blood clots there had been, but Reuters reports that Austria has also stopped using a batch of AstraZeneca shots while investigating a death attributed to coagulation disorders, along with an illness attributed to a pulmonary embolism, a condition where one or more of the lung’s arteries becomes blocked by a blood clot. Six other European countries have also reportedly halted the distribution of the COVID jab.

“Both we and the Danish Medicines Agency have to respond to reports of possible serious side-effects, both from Denmark and other European countries,” the director of the Danish Health Authority, Soren Brostrom, said in a statement.

The Danish Medicines Agency said the suspension would last for 14 days as authorities launch an investigation into the blood clots, with assistance from other EU member states.

NEW: Danish Health Authority says use of #AstraZeneca COVID19 #vaccine has been halted due to serious cases of blood clots. This follows similar suspension in Austria.

Here's a statement from the European Medicines Agency on the issue yesterday: pic.twitter.com/69WBgoujV1

— Julianna Tatelbaum (@CNBCJulianna) March 11, 2021

They did not say how many reports of blood clots there had been, but Austria has stopped using a batch of AstraZeneca shots while investigating a death from coagulation disorders and an illness from a pulmonary embolism.

AstraZeneca claims its vaccine is subject to strict and rigorous quality controls and that there have been “no confirmed serious adverse events associated with the vaccine.” It said it was in contact with Austrian authorities and would fully support their investigation.

“Both we and the Danish Medicines Agency have to respond to reports of possible serious side-effects, both from Denmark and other European countries,” the director of the Danish Health Authority, Soren Brostrom, said. “It is important to emphasize that we have not opted out of using the AstraZeneca vaccine, but that we are putting it on hold.”

The European Medicines Agency said Wednesday there is no evidence linking AstraZeneca to the two cases of blood clots in Austria. The company said the number of (thromboembolic events” (blood clots forming) in people who have received the AstraZeneca vaccine is no higher than that seen in the general population, with 22 cases of such events being reported among the 3MM people who have received it as of March 9.

And at least one investor claimed Denmark’s suspension of AstraZeneca’s COVID vaccine on blood clot concerns shows “the detection systems that look for potential safety issues are working,” and that most of these “safety events” would ultimately be linked to natural processes, not the jab.

“It’s good to see the safety signal detection systems working and it’s important that any safety signal is followed-up using the correct protocols,” Shore analyst Adam Barker told Bloomberg. Data from the vaccine’s phase three trials suggests that “you would expect that most safety signals won’t ultimately be linked to the vaccine,” he said.

However, “it’s hard to make judgments on the impact on shareholder value,” he added, given there are “a lot of moving parts.” But ultimately, a risk-reward trade-off with any therapy; “you can only confidently make judgments on that decision when all the data is finalized and clear”

Nevertheless, shares of AZ tumbled on Thursday on signs that the European vaccine rollout is facing fresh skepticism and obstacles. Shares were down more than 2% in London’s mid-morning trade.

Whether Austria and other EU states will follow suit remains to be seen, though at least one other national health authority is reportedly considering a halt: the Norwegian Institute of Public Health and the Medicines Agency are meeting to discuss Denmark’s decision to halt vaccinations using doses of the vaccine, according to reports from state broadcaster NRK.