The European Medicines Agency (EMA) announced on Wednesday that unusual blood clots with low blood platelets should be listed as “very rare side effects” of AstraZeneca’s COVID-19 vaccine.
So far, most of the cases reported have occurred in women under 60 years of age within two weeks of vaccination. The regulator said that based on the currently available evidence, specific risk factors have not been confirmed.
The Pharmacovigilance Risk Assessment Committee (PRAC), the EMA’s safety committee, noted that the blood clots occurred in veins in the brain (cerebral venous sinus thrombosis, CVST) and the abdomen (splanchnic vein thrombosis) and in arteries, together with low levels of blood platelets and sometimes bleeding.
The PRAC concluded that a plausible explanation for the combination of blood clots and low blood platelets is an immune response, leading to a condition similar to one seen sometimes in patients treated with heparin.
Speaking at a press briefing on Wednesday afternoon, EMA Executive Director Emer Cooke started by saying that PRAC had confirmed that “the benefits of the AstraZeneca vaccine in preventing COVID-19 overall outweigh the risk of side effects.”
She said, “COVID-19 is a very serious disease with high hospitalisation and death rates, and every day Covid is still causing thousands of deaths across the EU. This vaccine has proven to be highly effective; it prevents severe disease and hositalisation and it is saving lives.”
“Based on the current available evidence, specific risk factors such as age, gender, or previous medical history of clotting disorders have not been able to be confirmed, as the rare events are seen in all ages and in men and women” Emer Cooke, EMA Executive Director
“Vaccination is extremely important in helping us in the fight against COVID-19 and we need to use the vaccines we have to protect us from the devastating effects.”
Cooke went on to say that the PRAC, after “very in-depth analysis” has concluded that the reported cases of unusual blood clotting following vaccination with the Astra Zeneca vaccine should be listed as “possible side effects of the vaccine.”
“Based on the current available evidence, specific risk factors such as age, gender, or previous medical history of clotting disorders have not been able to be confirmed, as the rare events are seen in all ages and in men and women.”
EU Health Commissioner Stella Kyriakides tweeted on Wednesday evening that she had held an “important meeting with EU health ministers following the EMA’s presentation of their assessment of AstraZeneca vaccine safety.”
She said, “Our decisions on vaccine rollouts should be based on science and with the safety of citizens at the centre. The AstraZeneca experience shows that our pharmacovigilance system works. But is essential that we follow a coordinated approach across the EU. We must speak with one voice across the EU to improve public trust in vaccinations.”
“Vaccination is extremely important in helping us in the fight against COVID-19 and we need to use the vaccines we have to protect us from the devastating effects” Emer Cooke, EMA Executive Director
Meanwhile in the UK, the Medicines and Healthcare products Regulatory Agency (MHRA) issued new advice on Wednesday, concluding a possible link between the AstraZeneca COVID-19 vaccine and extremely rare, unlikely-to-occur blood clots.
In a statement the MHRA said, “The benefits of vaccination continue to outweigh any risks but the MHRA advises careful consideration be given to people who are at higher risk of specific types of blood clots because of their medical condition.”