European countries including Germany, France and Italy are expected to resume administering the AstraZeneca/Oxford University vaccine after EU regulators deemed the jab safe to use following a careful review.
A number of EU member states had halted vaccination with the AZ/Oxford vaccine after reports of blood clots in people who had received the jab.
The European Medicines Agency’s safety committee PRAC concluded its preliminary review of the blood clot reports, confirming yesterday that the benefits of the AZ/Oxford vaccine continue to outweigh the risk of side effects.
The PRAC affirmed that the vaccine is not associated with an increase in the overall risk of blood clots, also referred to as thromboembolic events.
The committee did find, however, that the AZ/Oxford vaccine may be associated with very rare cases of blood clots associated with low levels of blood platelets (thrombocytopenia), including rare cases of clots in the vessels draining blood from the brain (CVST).
Around 20 million people in the UK and European Economic Area (EEA) had been given the AZ/Oxford vaccine as of 16 March.
The EMA reviewed seven cases of blood clots in multiple blood vessels – disseminated intravascular coagulation (DIC) – and 18 cases of CVST.
The regulatory agency said that a causal link between these cases and the vaccine has not been proven, but is ‘possible’ and that this deserves further analysis.
Records of DIC and CVST were considered in ‘extreme detail’ by PRAC’s experts – including nine cases of which resulted in death.
The EMA added that most of these cases were reported in people under the age of 55 years and the majority were women.
The committee, based on pre-COVID figures, calculated that less that one reported case of DIC might have been expected by 16 March among people under 50 within 14 days of receiving the vaccine, whereas five cases had been reported.
In addition, 1.35 cases of CVST may have been expected among this age group, whereas by the same cut-off date there had been 12.
The safety committee did not identify a similar imbalance in the older population who had received the vaccine.
Due to these preliminary findings, the PRAC will complete an additional review of these risks, including considering the risks with other types of COVID-19 vaccines.
The EMA will also continue its close safety monitoring of blood clotting reports, with further studies being instituted to provide further laboratory data on top of real-world evidence.
The PRAC was ultimately ‘of the opinion’ that the AZ/Oxford’s efficacy in preventing COVID-19 hospitalisations and death outweighs the very rare likelihood of developing a blood clotting disorder.
The UK’s Medicines and Healthcare products Regulatory Agency (MHRA), following its own scientific review of all the available data, concluded the evidence does not suggest that blood clots in veins are caused by the AZ/Oxford vaccine.
Similarly to the EMA, the MHRA is conducting a further review into five UK reports of the very rare and specific type of blood clot in the cerebral veins – known as sinus vein thrombosis – occurring alongside thrombocytopenia.