BERLIN — Danish and Norwegian authorities said Thursday that they have temporarily suspended the Oxford-AstraZeneca vaccine, citing concerns over a possible association with blot clots, even as the European Union’s regulator found no evidence that the vaccine is unsafe.
“We are engaged in the largest and most important vaccination rollout in Danish history. And right now, we need all the vaccine doses we can get,” said Soren Brostrom, director of the Danish National Board of Health, in a statement on Thursday. “It is, therefore, not an easy decision to pause vaccination with one of the vaccines. However, because we vaccinate so many people, we also need to react with due diligence when we learn of possible and severe side effects.”
Danish authorities said that one death in Denmark is being investigated.
None of the coronavirus vaccines authorized in Europe or the United States have yet been linked to deaths, in clinical trials or real-world settings.
While the Danish suspension is expected to last two weeks, Norwegian authorities did not immediately provide a timeline for their review of the vaccine.
Concerns were first prompted by a case in Austria of a person who was diagnosed with blood clots and died 10 days after vaccination. At least three other people who received AstraZeneca vaccines from the same batch also developed serious conditions, the European Medicines Agency (EMA) said Wednesday.
But the EMA concluded there “is currently no indication that vaccination has caused these conditions, which are not listed as side effects with this vaccine.” It added that the prevalence of blood clots in vaccinated people “is no higher than that seen in the general population.”
In its release, the EMA said “although a quality defect is considered unlikely at this stage,” it would investigate the quality of the relevant batch of vaccines — a shipment of 1 million AstraZeneca doses distributed to 17 European countries.
Several affected nations had already said they would not use the batch’s doses until further notice. Thursday’s announcement by Denmark appeared to go further, as it applied to all AstraZeneca coronavirus vaccine doses in the country of 5.8 million people.
Norway did not receive doses from the batch that is under scrutiny, according to the EMA.
In Britain, where more than 11 million doses of the vaccine have already been administered, the country’s regulator reassured people on Thursday that they “should still go and get their COVID-19 vaccine when asked to do so.”
“It has not been confirmed that the report of a blood clot, in Denmark, was caused by the COVID-19 Vaccine AstraZeneca,” said Phil Bryan, a senior official with the British regulator, according to the statement. “Blood clots can occur naturally and are not uncommon.”
In a statement of its own, AstraZeneca said “the safety of the vaccine has been extensively studied in Phase III clinical trials and Peer-reviewed data confirms the vaccine has been generally well tolerated.”
Denmark’s response to the pandemic has at times been more cautious than that of other E.U. members. The country’s government ordered the culling of millions of minks last year amid concerns that animals infected with the coronavirus could prompt the emergence of vaccine-resistant variants.
Still, the Danish and Norwegian moves could put pressure on other European nations to impose similar temporary suspensions, which may throw into further disarray the bloc’s vaccination strategy that has already been mired by backlogs and mixed political messaging.
The chief epidemiologist of Iceland, which like Norway is not a member of the E.U., said Thursday that the country would also temporarily suspend use of the AstraZeneca vaccine, according to a spokesman for the Icelandic Foreign Ministry. But the spokesman could not immediately say whether that suspension would only apply to the batch under scrutiny or to all AstraZeneca coronavirus vaccines in the country.