Denmark has ceased giving the Oxford-AstraZeneca Covid vaccine amid concerns about rare cases of blood clots, the first European country to do so fully, according to the BBC.

The move is expected to delay the country's vaccination program by several weeks.

Danish officials said that all 2.4 million doses of the AstraZeneca vaccine would be withdrawn until further notice.

The Danish Health Authority said studies had shown a higher than expected frequency of blood clots following doses, affecting about one in 40,000 people.

It comes after two cases of thrombosis in Denmark were linked to vaccinations, AFP reported. One of the cases, in a 60-year-old woman, was fatal.

MarketWatch says the Danish Health Authority said on Wednesday that, following its own review, the country’s vaccine rollout would continue without the AstraZeneca shot, as it warned of a “real risk of severe side effects.”

Drug watchdog the European Medicines Agency last week announced a possible link with clots but said the risk of dying of Covid-19 was much greater.  Several European countries had previously briefly suspended the jab.  Most have now resumed vaccinations with AstraZeneca, but often with limits to older age groups.

The United States, Canada and the European Union reportedly paused the Johnson & Johnson vaccine for similar reasons over clotting.

South Africa has also paused its use, despite the Johnson & Johnson being its preferred vaccine because of its effectiveness against the South African variant, the BBC said.