Claim: European countries stopped using the Oxford-AstraZeneca Covid-19 vaccine after cases of blood clots were reported.
Fact: Some European countries temporarily paused the use of Oxford-AstraZeneca’s vaccine. At least 18 of these countries have now removed the pause.
Thromboembolic Events with Blood Clots
During the first three weeks of March, countries across Europe temporarily paused vaccination with Vaxzervia, better known as Oxford-AstraZeneca’s vaccine. The pause came after several reports of thromboembolic events which involved blood clots and other symptoms like low platelet count and bleeding. The reported cases included deep vein thrombosis (DVT) and pulmonary embolisms, as well as disseminated intravascular coagulation (DIC) and cerebral venous sinus thrombosis (CVST). Of these, CVST is considered to be a rare and unique thromboembolic event and this is what led many countries to pause the vaccine.
Pause in Oxford-AstraZeneca
Between 7 March and 20 March, 20 countries of the European Economic Area temporarily paused use of Oxford-AstraZeneca’s Covid-19 vaccine, while two countries paused a particular batch, after reports of hemorrhage, platelet deficiency and thrombosis were found in various countries. These countries included: Austria, Estonia, Latvia, Lithuania, Denmark, Norway, Iceland, Romania, Italy, Bulgaria, Ireland, France, Portugal, Cyprus, Slovenia, Germany, Netherlands, Finland, Sweden, and Luxembourg.
Eight countries of the EEA chose to not pause vaccination with Astra-Zeneca, while the UK took a similar decision.
Between 18th and 25th March, 15 of the 20 countries who had paused Oxford-AstraZeneca resumed its use, while France resumed it for people over the age of 55 and Sweden resumed it for those over 65. While Germany initially resumed the vaccine for younger people, at the end of March it restricted the vaccine’s use for those who are over the age of 60. On 25 March, Danish health authorities announced that they were extending the pause for three weeks. Norway announced a similar decision the same day.
Cases Reported
Austria was the first country to pause vaccination with Oxford-AstraZeneca’s vaccine on 7 March, after the death of a 49-year-old woman due to coagulation complications, as well as a report of a 35-year-old woman who developed a pulmonary embolism.
On 11 March, Denmark’s drug regulator reported one post-vaccination death of a woman with low blood platelet count, bleeding, and blood clots in small and large vessels. On 25 March, Denmark stated that two new cases of blood clots and platelet deficiency had been reported.
Norway reported five cases with a combination blood clots, bleeding and platelet deficiency, including one death. In addition, one young person died due to hemorrhaging and platelet deficiency.
On 16 March, Germany reported seven cases of thromboembolic events, of whom three had died. This included six cases of CVST in young to middle-aged women, as well as one death from a combination of cerebral hemorrhage, thrombosis, and platelet deficiency. By 19 March, this number had increased to 13 cases, 12 of which were women between the ages of 20 and 63.
The Netherlands reported two cases of low blood platelet count and thrombosis in patients over 50 years of age. The country’s Side Effect Center Lab reported that the nature of thrombosis in these cases was less severe than in other countries and the platelet deficiency was also not as severe.
On 20 March, Finland became one of the last countries to pause the vaccine, reporting two cases of CVST.
While these cases were the basis of the aforementioned countries’ temporary pause, this is not an exhaustive list of cases that were reported in Europe
Is AstraZeneca Safe?
While certain countries investigated reports on a national level, the EEA’s top drug regulator, the European Medicines Agency (EMA), gathered reports from various countries and investigated. The agency’s Pharmacovigilance Risk Assessment Committee (PRAC) reviewed the situation, sending out regular updates starting from 10 March.
EMA’s first press release stated that four cases of thromboembolic events had been reported after the use of one particular batch of AstraZeneca, including the two in Austria. Stressing that a quality defect with the batch was “unlikely”, EMA started investigating the batch, along with other reports of thromboembolic events and blood clots. As per the press release, 22 cases of thromboembolic events had been reported in the 3 million people who had been vaccinated with Oxford-AstraZeneca. EMA goes on to state that this number is now higher than what is seen in the general population and that there was currently no indication that these events were caused by the vaccine.
The next day, EMA reported that 30 cases of thromboembolic events had been found in 5 million people vaccinated with Astra-Zeneca. The agency reiterated that it was carrying out an investigation into reports of post-vaccination thromboembolic events and blood clots. Stressing once more that there was, so far, no indication of the vaccine causing these events, EMA also recommended that Oxford-AstraZeneca “can continue to be administered while investigations are going”.
On 15 March, EMA reiterated that many thousands of people suffer from blood clots annually and the number of thromboembolic events in the vaccinated population did not seem to be higher than that in the general population. The agency had begun an investigation into the matter to determine whether it was the vaccine that contributed to the thromboembolic cases that had been reported, or whether other causes had contributed to them. The press release stated that Oxford-AstraZeneca’s benefit in preventing illness and death from Covid-19 outweighed the risks it poses. This remained EMA’s official stance throughout its investigations.
The next day, EMA announced that the PRAC had made progress in its “detailed evaluation” of post-vaccination blood clots and thromboembolic events to determine if they held a causal relationship with Oxford-AstraZeneca. It reiterated its stance that the vaccine’s benefits outweigh its risks.
On 17 March, the World Health Organization (WHO) put out a press release stating that, “Vaccination against Covid-19 will not reduce illness or death from other causes.” WHO stressed that thromboembolic events occur “frequently” and that venous thromboembolism is “the third most common cardiovascular disease globally”.
In extensive vaccination campaigns, WHO went on to state, it’s “routine” for countries to report potential adverse events post-vaccination. While it is good practice to look into such cases, it is not necessary that they hold a causal relationship with the vaccine. Stating a similar stance to EMA, of the vaccine’s positive risk-benefit profile, WHO reported that its Global Advisory Committee on Vaccine Safety was looking into “the latest available safety data” for Oxford-AstraZeneca.
On 18th March, the PRAC held an “extraordinary” meeting to conclude the preliminary evaluation and make recommendations based on it. EMA stated that it had reviewed seven cases of DIC and 18 cases of CVST, reported in 20 million people who had been vaccinated with Oxford-AstraZeneca in the UK and EEA. Nine of these had resulted in death and the majority had occured in women under 55 years of age.
EMA stated that 469 cases of thromboembolic events had been reported in both studies before authorization of Oxford-Zeneca and after it had been rolled out. This number, according to the agency, was less than what is to be expected in the general population.
However, the press release also stated that, while one case of DIC would be expected by 16 March in people under 50 years of age, two weeks after they had been vaccinated, five such cases had been reported. Similarly, while 1.35 cases of CVST would be expected in the same age group, 12 cases had been reported by 16 March. No such abnormality was seen in older groups.
Despite this, EMA remained of the opinion that the vaccine was not associated with an overall risk of blood clots of thromboembolic events. It stated that there is no evidence of problems with one particular batch. While admitting that the vaccine could be associated with “rare” cases of platelet deficiency and CSVT, EMA reiterated its stance that Oxford-AstraZeneca’s benefits in preventing Covid-19 outweighed the risks. Lastly, EMA recommended that the vaccine’s product information be updated to communicate risk of thromboembolic events to health care professionals and the general public.
WHO released a similar press release the next day, stating that it had carried out a “careful scientific review” of clinical trial date and safety reports on Oxford-AstraZeneca. The press release stated that reported rates of thromboembolic events were in line with expected rates. According to the WHO, observed rates were less than expected thus Oxford-AstraZeneca is not associated with an overall increase in such events. WHO also stated that while CVST is a rare thromboembolic event, a causal relationship with the vaccine is not certain. WHO reiterated the stance that Oxford-AstraZeneca holds a positive risk-benefit profile and adequate information regarding symptoms of adverse amounts should be provided to healthcare professionals and those receiving the vaccine.
On 25th March, EMA released another press release reiterating its stance and stating that product information should be updated regarding potential risks. The PRAC is continuing its assessment of reported events and updated recommendations are expected between 6 April and 9 April.
Between 18th and 25th March, 15 of the 20 countries who had paused Oxford-AstraZeneca resumed its use, while France resumed it for people over the age of 55 and Sweden resumed it for those over 65. While Germany initially resumed the vaccine for younger people, at the end of March it restricted the vaccine’s use for those who are over the age of 60. On 25 March, Denmark stated that two new cases of blood clots and platelet deficiency had been reported. The same day, Danish health authorities announced that they were extending the pause for three weeks. Norway announced a similar decision the same day.
Expert Opinions
Germany’s Society of Society of Thrombosis and Haemostasis Research, led by Professor Andrea Greinacher of the University of Greifswald, conducted an investigation into the 13 reported cases of CVST. Their report, released on 19 March, stated that Oxford-AstraZeneca’s vaccine may lead to the creation of antibodies that react with the antigens of platelets, which are responsible for activating the platelets. This may lead to the activation of platelets in a manner that mimics heparin-induced thrombocytopenia (HIT), a disease in which platelets are activated and clump together to form blood clots.
The society went on to state that there was no evidence linking Oxford-AstraZeneca to an increased chance of DVT and pulmonary embolism. They further supported EMA’s stance that the benefits of the vaccine are greater than its risk and laid out a diagnosis and treatment plan for post-vaccination thromboembolic conditions.
In Norway’s Oslo University Hospital, Rikshospitalet, researchers investigated the cases of three people under the age of 50 who had developed blood clots. They found that the vaccine “most likely” leads to an immune response that creates antibodies, leading to the activation of platelets and consequent blood clot. According to the researchers, this also leads to a decrease of platelets in circulation leading to low platelet count.
Several experts have criticized the temporary pause instated by EEA countries. Stefano Nava, chief of respiratory and critical care at Sant’Orsola Hospital and a professor of respiratory medicine at University of Bologna in Italy, stated that the pause had convinced people that Oxford-AstraZeneca’s vaccine kills people, for which there is no proof. The pause, he said, would undermine public confidence in vaccination and could lead to Italians not wanting their second dose of the Oxford-AstraZeneca vaccine.
Dr Jean-Paul Oritz, a nephrologist at the Center of Nephrology in France, called the pause a “catastrophe” that would prove to be a “tough blow” to vaccination campaigns that would cause mistrust in vaccines..
Dr Michael Head, a senior research fellow in global health at the University of Southampton in the United Kingdom, called the decision “baffling”. He reiterated EMA’s stance of adverse incidents being the same in vaccinated populations as in the general population. The pause could lead to “delays in protecting people” and less confidence in vaccination, Head stated
Dr Stephen Griffin, an expert in virology and associate professor at University of Leeds’ School of Medicine, called the pause “disappointing”. According to Griffin, “the harm caused by depriving people of access to vaccine would likely vastly outweigh even the worst case scenario if any link to the clotting disorders is found,” given the upturn of Covid-19 cases in European countries. “Nationwide gestures” such as these, he further stated, would also fuel vaccine hesitancy and anti-vaccine sentiment.
Summary: Certain EEA countries paused use of the Oxford-AstraZeneca vaccine after reports of thromboembolic events, leading some to believe that the vaccine had been stopped in European countries. Soch Fact Check found that the pause in vaccination was temporary and has been removed in the majority of EEA countries.