Denmark suspended the use of the AstraZeneca vaccine because of concerns about possible links to an increased risk of blood clots, the Danish Health Authority announced on Thursday. Iceland and Norway later also announced suspensions in administering the shots.

Danish authorities said all use of the vaccine in the country would be 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.

Still, Danish health officials said they could not yet know if the clots — including a case in which a patient died — were caused by the vaccine, and that an investigation was launched to be “on the safe side.”

Within hours, the European Medicines Agency said in a statement that there is currently no indication the vaccine “has caused these conditions.” The agency, which is Europe’s main drug regulator, said the vaccine’s benefits continue to outweigh its risks, and countries can continue to administer the vaccine while the cases of blood clots are investigated.

The agency’s safety committee is already looking into all cases involving blood clots reported after AstraZeneca vaccinations.

Amid the flurry of suspensions, the Netherlands announced that it would continue to administer the AstraZeneca vaccine despite the concerns voiced by other countries.

The company did not have an immediate response to the suspensions.

Magnus Heunicke, the Danish minister of health, 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.”

The Danish Health Authority pointed to several such cases reported across Europe, including in Austria, and said that it would await further investigation by the E.M.A.

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.”

Just over 2 percent of the people in Denmark, a total of a little more than 142,000 in a population of six million, have been injected with the vaccine produced by AstraZeneca, a British-Swedish company.

On Wednesday, the E.M.A. 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 a 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.

As of Feb. 28, Britain had administered 9.7 million doses of the AstraZeneca vaccine, and the British medicine watchdog 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 British Medicines and Healthcare Products Regulatory Agency said.

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.”


https://www.nytimes.com/2021/03/11/world/astrazeneca-vaccine-denmark.html