Denmark suspended the use of the AstraZeneca vaccine because of concerns about links to an increased risk of blood clots, the Danish Health Authority announced on Thursday.
All use of the vaccine is now halted for at least 14 days after several severe cases of clots were reported among people who had received the shot, the national broadcaster DR reported.
The Danish Medicines Agency said in a statement that it was investigating the death of a person vaccinated with the AstraZeneca shot who developed a blood clot.
The Danish minister of health, Magnus Heunicke, posted a message on Twitter confirming that the use of the AstraZeneca vaccine had been suspended, “following a signal of possible serious side effects in the form of fatal blood clots.”
“It is currently not possible to conclude whether there is a connection,” he added. “We acted early, it needs to be thoroughly investigated.”
A total of just over 142,000 people in Denmark, which has a population of about six million, have been injected with the vaccine produced by AstraZeneca, a British-Swedish company.
As of Feb. 28, Britain had administered 9.7 million doses of the AstraZeneca vaccine. The British medicine watchdog, the Medicines and Healthcare Products Regulatory Agency, has not publicly outlined any concerns about blood clots. “The number and nature of suspected adverse reactions reported so far are not unusual in comparison to other types of routinely used vaccines,” the agency said.
In the statement from the Danish Medicines Agency, Tanja Erichsen, a divisional director, said, “We do not yet know whether the blood clots and the Danish death is caused by the vaccine, but it is being thoroughly investigated right now to be on the safe side.”
The Danish Health Authority pointed to several such cases reported across Europe and said that it would await further investigation by the European Medicines Agency, the drug regulatory body for the European Union.
On Wednesday, the European agency said there was no indication that two Austrian cases — one in which a patient died after blood clots formed and another in which a patient was hospitalized with a similar condition — were related to the use of the vaccine.
The use of the specific batch of the vaccine that led to the cases in Austria was suspended in the country, and subsequently also in Estonia, Latvia, Lithuania and Luxembourg. The European Medicines Agency said a quality defect was “unlikely” but said that the batch would be investigated further.
Soren Brostrom, director of the National Board of Health in Denmark, said: “We are in the middle of the largest and most important vaccination rollout in Danish history. And right now we need all the vaccines we can get. Therefore, putting one of the vaccines on pause is not an easy decision.”
“But precisely because we vaccinate so many,” he added, “we also need to respond with timely care when there is knowledge of possible serious side effects.”