AstraZeneca Offers Reassurance on Safety of COVID-19 Vaccine, Following Blood Clot Concerns

There have been 15 events of deep vein thrombosis and 22 events of pulmonary embolism reported across the European Union and United Kingdom.

Following the suspension of AstraZeneca’s COVID-19 vaccine in several countries amid concerns about blood clots, the company has released a statement offering reassurance on the vaccine’s safety, saying a review of all available data found no increased risk of thrombotic events.1

French leaders announced on Monday that the country will be suspending use of the AstraZeneca COVID-19 vaccine at least until Tuesday afternoon, when a recommendation is expected from the European Medicines Agency.2 German officials also said they would temporarily halt the use of the vaccine as a precaution following reports that some recipients developed blood clots after being vaccinated.2

According to reporting by Reuters, officials in Ireland, Denmark, Norway, Iceland, and the Netherlands have also suspended use of the vaccine. Austria also stopped using a batch of AstraZeneca shots last week amid an investigation of a death from coagulation disorders.3

“A careful review of all available safety data of more than 17 million people vaccinated in the European Union (EU) and UK with COVID-19 Vaccine AstraZeneca has shown no evidence of an increased risk of pulmonary embolism, deep vein thrombosis (DVT) or thrombocytopenia, in any defined age group, gender, batch, or in any particular country,” the company said a press release.1

According to the press release, there have been 15 events of deep vein thrombosis and 22 events of pulmonary embolism reported across the European Union and United Kingdom. This is lower than would be expected to occur naturally in a population of this size and is similar across other COVID-19 vaccines, according to AstraZeneca.1

The release also noted that in clinical trials, the number of thrombotic events were lower in the vaccinated group than in control groups. Researchers found no evidence of increased bleeding in more than 60,000 participants enrolled.1

“Around 17 million people in the EU and UK have now received our vaccine, and the number of cases of blood clots reported in this group is lower than the hundreds of cases that would be expected among the general population,” said Ann Taylor, MD, chief medical officer at AstraZeneca, in the press release.1

Statements from the European Medicines Agency and the World Health Organization have reiterated the safety of the vaccine, according to Reuters.3 The press release from AstraZeneca said that additional testing is being conducted both by the company and by independent European health authorities, and none of these re-tests have found causes for concern.1

“The nature of the pandemic has led to increased attention in individual cases, and we are going beyond the standard practices for safety monitoring of licensed medicines in reporting vaccine events, to ensure public safety,” Taylor concluded in the press release.1

REFERENCE

1. Update on the safety of COVID-19 Vaccine AstraZeneca [news release]. AstraZeneca; March 14, 2021. https://www.astrazeneca.com/content/astraz/media-centre/press-releases/2021/update-on-the-safety-of-covid-19-vaccine-astrazeneca.html. Accessed March 15, 2021.

2. Jordans F. Germany, France suspend use of AstraZeneca vaccine. Associated Press; March 15, 2021. https://apnews.com/article/germany-suspends-astrazeneca-vaccine-blood-clotting-0ab2c4fe13370c96c873e896387eb92f. Accessed March 15, 2021.

3. AstraZeneca finds no evidence of increased blood clot risk from vaccine. Reuters; March 14, 2021. https://www.reuters.com/article/us-health-coronavirus-astrazeneca-vaccin/astrazeneca-finds-no-evidence-of-increased-blood-clot-risk-from-vaccine-idUSKBN2B60KO. Accessed March 15, 2021.