After further investigation of cases of thromboembolic events and other conditions related to blood clots reported after vaccination with COVID-19 Vaccine AstraZeneca, the Pharmacovigilance Risk Assessment Committee (PRAC) of the European Medicines Agency (EMA) has concluded that the benefits of the vaccine still outweigh the risks, despite possible link to rare blood clots with low blood platelets.
While the investigation is still ongoing, PRAC has recommended updating the summary of product characteristics (SmPC) and package leaflet of COVID-19 Vaccine AstraZeneca to reflect the current knowledge of this safety issue. A direct healthcare professional communication (DHPC) will be sent to healthcare professionals prescribing, dispensing or administering the vaccine. The DHPC will also be published on a dedicated page on the FAMHP and EMA websites.
Recommendations for healthcare professionals and vaccinated people
Healthcare professionals should be alert to signs and symptoms of thromboembolism and/or thrombocytopenia.
Recipients should be warned to seek immediate medical attention if they develop symptoms such as shortness of breath, chest pain, leg swelling or persistent abdominal pain after vaccination. In addition, anyone with neurological symptoms, including severe and persistent headaches or blurred vision after vaccination, or who experiences skin bruising (petechiae) beyond the site of vaccination after a few days, should seek immediate medical attention.
The Belgian Superior Health Council (SHC) also recommends continuing vaccination with COVID-19 Vaccine AstraZeneca, as with other vaccines.
As for the risk of thrombocytopenia and coagulation disorders, the SHC recommends for all vaccinated people, irrespective of the vaccine:
- to continue their usual treatment (including antithrombotic treatment),
- not to take preventive antithrombotic medicines in the context of vaccination.
General information on the safety issue
A combination of thrombosis and thrombocytopenia, in some cases accompanied by bleeding, has been observed very rarely following vaccination with COVID-19 Vaccine AstraZeneca in several countries of the European Economic Area (EEA). Some cases have led to local suspensions of specific batches or to the use of the vaccine itself. This includes severe cases presenting as venous thrombosis, including unusual sites such as cerebral venous sinus thrombosis (CVST), mesenteric vein thrombosis, as well as arterial thrombosis, concomitant with thrombocytopenia. The majority of these cases occurred within the first seven to fourteen days following vaccination and occurred in women under 55 years of age, however this may reflect the increased use of the vaccine in this population. Some cases had a fatal outcome.
Based on these events, PRAC has initiated signal procedure. A full investigation has been performed under accelerated timetable. Reports of blood clots and thrombocytopenia in individuals who received the vaccine have been reviewed paying special attention to the information on the sex, age, risk factors, COVID-19 diagnosis (if available), time-to-onset, outcome, and clinical entity.
The investigation also included a related literature review and an observed to expected analysis conducted with EudraVigilance case reports (with the following terms: (cerebral) venous sinus thrombosis, disseminated intravascular coagulation and thrombotic thrombocytopenic purpura).
Reporting of side effects and additional information
You can report side effects via www.eenbijwerkingmelden.be.
In order to speed up the identification of severe and unknown side effects of COVID-19 vaccines, we ask you to promptly report these side effects.
Known side effects are described in the SmPC and package leaflet, and the most frequent side effects can be found here. The FAMHP also publishes a weekly overview of all reported adverse reactions.