The move was described by Danish officials as “precautionary” and there has been no confirmed link between the blood clots and the vaccine. Any possible complications would likely stem from a specific batch, rather than indicating a wider issue.
Austria has also stopped using a batch of AstraZeneca doses while investigating a death from coagulation disorders and an illness from a pulmonary embolism. Four other countries have also paused the rollout while an investigation is carried out.
Denmark said it would suspend use of the AstraZeneca jab for 14 days after a 60-year old woman, who was given an AstraZeneca shot from the same batch that was used in Austria, formed a blood clot and died.
“Both we and the Danish Medicines Agency have to respond to reports of possible serious side-effects, both from Denmark and other European countries,” the director of the Danish Health Authority, Soren Brostrom, said in a statement.
“It is currently not possible to conclude whether there is a link. We are acting early, it needs to be thoroughly investigated,” Magnus Heunicke, the Danish health minister, said on Twitter.
Geir Bukholm, director of infection prevention and control at the Norwegian Institute of Public Health (FHI), told a news conference the suspension was a “cautionary decision”. The FHI did not say how long the suspension would last.
Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene and Tropical Medicine, described the suspension of vaccinations as a “super-cautious approach based on some isolated reports in Europe”.
He said: “The problem with spontaneous reports of suspected adverse reactions to a vaccine are the enormous difficulty of distinguishing a causal effect from a coincidence.
“This is especially true when we know that Covid-19 disease is very strongly associated with blood clotting and there have been hundreds if not many thousands of deaths caused by blood clotting as a result of Covid-19 disease. The first thing to do is to be absolutely certain that the clots did not have some other cause, including Covid-19.
“A sensible approach is to investigate and be sure that the benefit and risk balance is in favour of the vaccine.
“Since we know with great certainty that the vaccine prevents Covid-19 with its attendant disease, and we are almost totally uncertain that the vaccine can have caused this problem, the risk and benefit balance is still very much in favour of the vaccine in my view.
“If, however, there is no shortage whatsoever of alternative vaccines, then an extreme precautionary approach as taken in Denmark may be justified; if however this action stops some people getting the vaccine who are then vulnerable to Covid-19, then it is a mistaken use of precaution.
“As far as one can tell there has not been a 'signal' of such problems in the UK and even if there were a 'signal', based on spontaneous reports, there needs to be a proper, rapid, epidemiological study to see if it is coincidence or not.”
The European Union’s drug regulator, the European Medicines Agency, said on Wednesday there was no evidence so far linking AstraZeneca’s jab to the two cases in Austria.
Estonia, Lithuania, Luxembourg and Latvia have also stopped inoculations from the batch while an investigation continues, the EMA said. The batch of 1 million doses went to 17 EU countries.
Italy also said on Thursday it would suspend use of an AstraZeneca batch, but one that was different to the batch used in Austria.
AstraZeneca has insisted the safety of its vaccine has been extensively studied in human trials, and there were “no confirmed serious adverse events associated with the vaccine”.
So far, 136,090 Danes have received a AstraZeneca jab and millions more have globally.
The UK government said in its latest weekly “yellow card” review, used to highlight side effects or adverse reactions, that for both the AstraZeneca and Pfizer jabs the “overwhelming majority of reports relate to injection-site reactions (sore arm for example) and generalised symptoms such as ‘flu-like’ illness, headache, chills, fatigue (tiredness), nausea (feeling sick), fever, dizziness, weakness, aching muscles, and rapid heartbeat”, adding that “generally, these happen shortly after the vaccination and are not associated with more serious or lasting illness”.
Additional reporting by Reuters
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