Denmark will prolong its suspension of AstraZeneca's Covid-19 shots by three weeks, pending further investigations into a potential link between the vaccine and rare cases of blood clots.
Denmark was among the first countries in Europe this month to suspend the use of the vaccine after reports of a small number of unusual cases of blood clots, registered both in Denmark and elsewhere.
"Our basis for making a final decision on the further use of the Covid-19 vaccine by AstraZeneca is too uncertain," director of the Danish Health Authority, Soren Brostrom, said in a statement.
"Many studies have been launched, but we do not yet have any conclusions. That is why we have decided to extend the suspension."
Most countries which temporarily suspended the vaccine have now resumed administering shots following recommendations from the European Union's drug watchdog and the World Health Organisation (WHO).
'Unusual disease picture'
Both the European Medicines Agency (EMA) and the WHO said last week the benefits of AstraZeneca's vaccine outweighed the risks.
"It cannot be ruled out... that there may be a connection between the vaccine and the very unusual disease picture that we are looking at," Danish Medicines Agency director Tanja Erichsen told a press briefing on Thursday.
Danish authorities will await results of further investigations, Ms Erichsen said.
An EMA review covering 20 million people who took the AstraZeneca shot in the UK and the European Economic Area, which links 30 European countries, included seven cases of blood clots in multiple blood vessels and 18 cases of a rare condition that is difficult to treat called cerebral venous sinus thrombosis (CVST), it said.
The uncertainty surrounding the vaccine seems to have had an effect on Danish confidence. A survey this week indicated that one in three Danes would decline using the AstraZeneca vaccine.
Only seven per cent would decline regardless of which Covid-19 vaccine was on offer.
Approximately 150,000 people had already received AstraZeneca's shot in Denmark before it was suspended.