Denmark, Norway study finds raised blood clot rates after AstraZeneca vaccine shot

Denmark and Norway have found a ‘slight rise’ in the blood clots among those inoculated with the AstraZeneca jab, a new study published in the peer-reviewed journal BMJ has found. According to the findings, there was a spike in rates of vein blood clots including clots in the brain, compared with expected rates in the general population. However, the researchers stress that the risk of such adverse events is considered “low”. Scientists assembled data from those who were recently administered their first dose of the Oxford-AstraZeneca vaccine. Denmark and Norway’s analysis came after European Medicines Agency (EMA) stated earlier in a report that it had found a “possible link” between the AstraZeneca shot and the rare fatal blood clots without any age restrictions. 

However, in the recent study, the UK and European medicine regulators said that when the incidences were compared with the total population that received the AstraZeneca-Oxford jab, the benefits of the vaccine still outweigh the risks. Although, Denmark and Norway have both suspended the use of the vaccine as several other EU countries have. Denmark was also the first country to suspend the use of US’ Johnson & Johnson COVID-19 shot over reports of blood clots. While the research analysis published by BMJ argued that the related condition impacted only a low percentage of those vaccinated, the Danish health authority, last week, said at a news conference that the benefits of suspended jabs did not outweigh its risks, adding that the pandemic was “under control”. Deputy director-general Helene Probst told Danish media outlets that the country plans to expand inoculation for the younger and healthier population and it did not want to stake the risks.

“In the midst of pandemic, this has been a difficult decision to make as we have had to discontinue using the Covid-19 vaccine from AstraZeneca,” Probst told reporters.

Side effects within 28 days of getting first shot

As many as 280,000 people aged 18-65 received a first dose of the Oxford-AstraZeneca COVID-19 vaccine in Denmark and Norway from February 2021 through to 11 March 2021. Scientists extracted the data from the national health records and identified a range of side effects such as cardiac arrest, strokes, deep vein blood clots and bleeding events within 28 days of receiving a first AstraZeneca vaccine dose, according to the BMJ study. “Researchers found 59 blood clots in the veins compared with 30 expected, corresponding to 11 excess events per 100,000 vaccinations. This included a higher than expected rate of blood clots in the veins of the brain, known as cerebral venous thrombosis (2.5 events per 100,000 vaccinations),” said the study.