Denmark and Norway have suspended use of AstraZeneca's COVID-19 vaccine amid reports of blood clotting in some people who received the jab.
Health authorities said it was a step taken as a "precaution" with no direct link yet between the clots and the jab.
But it's yet more negative publicity for AstraZeneca, the Swedish-British multinational pharmaceutical company, already under the spotlight over vaccine production delays and the efficacy of its jab, which is produced with the University of Oxford.
What do we know about the AstraZeneca vaccine?
The vaccine has several advantages: it is considerably cheaper and easier to handle than the Pfizer and Moderna vaccines and has been given a green light by several regulators including the UK, EU and World Health Organization.
Regulators have said the vaccine causes only mild to moderate side effects and is safe and effective at preventing COVID-19.
The jab is based on a genetically-altered common cold virus from chimpanzees.
The UK medicines regulator is encouraging people to continue to get their COVID vaccines despite reports from other European countries about halting the vaccination campaign.
"Reports of blood clots received so far are not greater than the number that would have occurred naturally in the vaccinated population," said Dr Phil Bryan, the UK Medicines and Healthcare products Regulatory Agency's vaccines safety lead.
Some EU countries suspend AstraZeneca jabs amid blood clot reports
The Danish health authority said on Thursday that it would halt AstraZeneca vaccinations after there was a reported death in the country.
But the health authority emphasised, nonetheless, that "at present, it cannot be concluded whether there is a link between the vaccine and the blood clots".
The Norwegian health authority also chose to halt vaccinations after the report from the Danish health authority. Both decisions will impact their vaccine schedules.
"It has not been concluded that there is a connection between vaccination and the incident in Denmark, but as a precaution, we choose to put vaccination with the AstraZeneca vaccine on pause while the investigation is ongoing," said Geir Bukholm, director of Infection Prevention and Control at the Norwegian Institute of Public Health.
It came after Austria suspended a batch of vaccines following the death of a woman due to blood clots and the hospitalisation of another person with a blockage in the arteries of the lungs.
The vaccine batch, which comprised one million doses delivered to 17 EU countries, had been suspended in four other states, Estonia, Lithuania, Luxembourg and Latvia, as a precaution.
The European Medicines Agency said they were reviewing the incidents as well as all other "conditions related to blood clots" but that a preliminary review suggested there was no "specific issue" with the batch.
As of Tuesday, the medicines regulator said, there were 22 cases of blood clotting reported among the three million people vaccinated with the AstraZeneca vaccine in the European Economic Area.
"There is good evidence that the vaccine is both safe and effective," said Søren Brostrøm, Director General of the Danish Health Authority.
"But both we and the Danish Medicines Agency have to react to reports of possible serious side effects, both from Denmark and other European countries. It shows that the monitoring system works."
Dr Simon Kolstoe, from the University of Portsmouth, told Euronews he was "surprised" by the countries that stopped using the vaccine amid the blood clot reports.
He pointed out that "so many people are being given the vaccines that there's going to be plenty of other health things that will just happen normally, whether or not the vaccine was given to people or not.
"I think that was perhaps a bit of an overreaction because you see these sorts of things happen whenever any new drugs come out," Kolstoe said.
"And I think there is just simply not very strong evidence at all to show that the AstraZeneca vaccine causes or has caused these things."
Supply row with the European Union
AstraZeneca had previously made headlines over production delays in the EU, an announcement that further slowed the bloc's vaccination rollout.
Company representatives told the European Union in late January, shortly before the vaccine was approved in the bloc, that they would not be able to supply the number of doses that was originally agreed upon in the first quarter of the year.
“The European Union wants the ordered and pre-financed doses to be delivered as soon as possible. And we want our contract to be fully fulfilled,” said Commissioner Stella Kyriakides in a stern statement about the promised doses on January 25.
The back and forth sparked a public dispute with the company. AstraZeneca CEO Pascal Soriot claimed that the contract only required them to make their best effort towards producing the doses.
It prompted the EU to release a redacted version of the vaccine contract which stated that AstraZeneca should use its “best reasonable efforts” to manufacture initial European doses.
The EU eventually introduced an export control mechanism to ensure it could review shipments of vaccine doses produced on the continent. In particular, it wanted to make sure doses were not being shipped to the United Kingdom, which had not been facing an AstraZeneca supply delay.
Soriot said the UK had signed their contract earlier than the European Union and said the production delays were at vaccine plants on the continent.
European parliamentarian Dr Peter Liese told Euronews this week that the company continued to have problems with production.
"They delivered only 10 per cent of what was promised and they claim that there is a problem with the supply chain, which is maybe true, but also that doesn't really give trust to the structure of the company if they have such a serious problem," Liese said.
The row prompted criticism of the EU vaccine purchasing contracts. Some experts have said that the bloc should have thrown more money at coronavirus vaccines.
"We have to admit that the United States invested a lot in the vaccine production and development and we need to learn from this," MEP Liese pointed out, referring to the US' speedy vaccination rollout as well. But, he added that European production was supplying vaccines globally.
AstraZeneca CEO Pascal Soriot told MEPs that the vaccine yield would improve and that they would catch up to the volume that they were meant to produce.
Early questions about dosing regimen and vaccine efficacy
AstraZeneca had previously been criticised about the vaccine's efficacy, despite performing well in Phase III trials in November.
The company's first press release about the vaccine's efficacy said it was 90% effective if administered at a half dose and then at a full dose and 62% effective at preventing COVID-19 if administered in two full doses.
Mene Pangalos, head of biopharmaceuticals research and development at AstraZeneca revealed to Reuters and the NY Times that a “mistake” had resulted in a lower dose of the vaccine being more effective but experts had criticised the use of an average between the two dosing regimens to determine the efficacy of the vaccine.
Medicines regulators in the UK and EU authorised the full dose of the vaccine but allowed for a longer interval between doses citing favourable results in the trial.
But after its approval, the vaccine was subject to questions about its efficacy in older individuals.
German authorities said they would not recommend the AstraZeneca vaccine for individuals over the age of 65 and other European countries followed their step citing a lack of information about older individuals in the trial.
France then reversed its decision and said that individuals between the ages of 65 and 74 could get the vaccine.
The European Medicines Agency has meanwhile recommended authorising the vaccine for anyone over the age of 18 qualifying that there were "not yet enough results in older participants (over 55 years old) to provide a figure for how well the vaccine will work in this group."
"However, protection is expected, given that an immune response is seen in this age group and based on experience with other vaccines," the EMA said.
Despite the headlines, AstraZeneca's vaccine shown to reduce severe COVID-19
Studies in the United Kingdom have shown that even a single dose of the AstraZeneca vaccine reduced hospitalisation dramatically.
A pre-print study in Scotland of nearly 500,000 people who received the vaccine showed that just a single dose of the vaccine reduced hospitalisation by 94%.
"The majority of those in the study who received COVID-19 Vaccine AstraZeneca were over 80 years old, and the effects of the vaccine were seen to be comparable across all age groups," the company said in a statement
"This data provides further evidence that the vaccine protects against severe COVID-19 outcomes, particularly in older populations who are at the highest risk."
What does AstraZeneca say?
"Patient safety is the highest priority for AstraZeneca," the company said in a statement to Euronews.
"Regulators have clear and stringent efficacy and safety standards for the approval of any new medicine, and that includes COVID-19 Vaccine AstraZeneca.
"The safety of the vaccine has been extensively studied in phase III clinical trials and peer-reviewed data confirms the vaccine is generally well tolerated.”
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