Cases of blood clots and other thromboembolic events after vaccination with COVID-19 Vaccine AstraZeneca [AZD-1222] are being reviewed by the safety committee of the European Medicines Agency (EMA), the Pharmacovigilance Risk Assessment Committee (PRAC), however, the PRAC considers that benefits of the vaccine outweigh the risks and therefore vaccination can continue while the investigation is ongoing.1,1
The EMA launched the investigation as a precautionary measure after the Danish Health Authority paused its AZD-1222 vaccination campaign after blood clots were reported in a patient who died. There is currently no indication that AZD-1222 vaccination has caused blood clots, and thromboembolic events are not listed as adverse events of this vaccine. The number of thromboembolic events in adults who have been vaccinated is no higher than the number reported in the general population, according to EMA.
As of 10 March 2021, 30 cases of thromboembolic events had been reported after vaccination with AZD-1222 in approximately 5 million adults in the European Economic Area, said EMA.
On 15 March 2021, the EMA reported that several authorities responsible for national vaccine campaigns in EU countries have temporarily paused vaccination with COVID-19 Vaccine AstraZeneca, as a precautionary measure while EMA investigates cases of blood clots.
EMA is working closely with AstraZeneca, experts in blood disorders, and with other health authorities including the UK Medicines and Healthcare products Regulatory Agency (MHRA) which has monitored the administration of approximately 11 million doses of AZD-1222. The review of thromboembolic events with COVID-19 Vaccine AstraZeneca is being carried out in the context of a safety signal, under an accelerated timetable.
Rigorous analysis of all the data related to thromboembolic events will be carried out, and PRAC will hold an extraordinary meeting on 18 March 2021 to report its conclusions on the information gathered and any further actions that may need to be taken.
While its investigation is ongoing, EMA currently remains of the view that "the benefits of the AstraZeneca vaccine in preventing COVID-19, with its associated risk of hospitalisation and death, outweigh the risks of side effects".
References
- 1. EMA. COVID-19 Vaccine AstraZeneca: PRAC investigating cases of thromboembolic events - vaccine's benefits currently still outweigh risks - Update. Internet Document : 11 Mar 2021. Available from: URL: https://www.ema.europa.eu/en/news/covid-19-vaccine-astrazeneca-prac-investigating-cases-thromboembolic-events-vaccines-benefits
- 2. EMA. EMA's safety committee continues investigation of COVID-19 Vaccine AstraZeneca and thromboembolic events - further update. Internet Document : 15 Mar 2021. Available from: URL: https://www.ema.europa.eu/en/news/emas-safety-committee-continues-investigation-covid-19-vaccine-astrazeneca-thromboembolic-events