Several European countries have suspended all or part of their AstraZeneca vaccine roll-out as a precaution while they investigate concerns relating to blood clots, but French and EU regulators say there is “no need” to halt vaccinations. 

Danish health authorities suspended all AstraZeneca vaccinations for two weeks after a 60-year old woman who had been vaccinated formed a blood clot and died.

The move “follows reports of serious cases of blood clots among people vaccinated with AstraZeneca’s Covid-19 vaccine”, the Danish Health Authority said in a statement.

But it cautiously added that “it has not been determined, at the time being, that there is a link between the vaccine and the blood clots”.

Norway soon followed suit, suspending all AstraZeneca vaccinations.

Austria earlier announced it had suspended the use of a batch of AstraZeneca vaccines after a 49-year-old nurse died of “severe blood coagulation problems” days after receiving an anti-Covid shot.

Four other European countries – Estonia, Latvia, Lithuania and Luxembourg – have also suspended the use of vaccines from this batch, which was sent to 17 European countries and consisted of one million jabs.

‘No causal link’

Other countries, including France, have said they will continue to administer the vaccine, citing the EU drug regulator’s ruling that the AstraZeneca jab was still safe to use.

French Health Minister Olivier Véran said he had consulted with the French medicines agency, which said there was “no need” to suspend vaccinations.

His Spanish counterpart, Carolina Darias, said that “so far, no causal link between the vaccine and the blood clot events has been established”.

On Wednesday, EMA, Europe’s medicines watchdog, said a preliminary probe showed that the batch of AstraZeneca vaccines used in Austria was likely not to blame for the nurse’s death.

As of March 9, 22 cases of blood clots had been reported among more than three million people vaccinated in the European Economic Area, the EMA said.

Some health experts said there was little evidence to suggest the AstraZeneca vaccine should not be administered and that the cases of blood clots corresponded with the rate of such cases in the general population.

“This is a super-cautious approach based on some isolated reports in Europe,” Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene & Tropical Medicine.

“The problem with spontaneous reports of suspected adverse reactions to a vaccine is the enormous difficulty of distinguishing a causal effect from a coincidence,” he said, adding that the Covid-19 disease was very strongly associated with blood clotting.

AstraZeneca said the safety of its vaccine had been extensively studied in human trials and peer-reviewed data had confirmed the vaccine was generally well tolerated.