By Erin Coates
A link between AstraZeneca’s COVID-19 vaccine and rare blood clots in the brain has been discovered, but officials have yet to identify a possible cause, according to a senior European Medicines Agency official.
“In my opinion, we can now say it, it is clear that there is an association (of the brain blood clots) with the vaccine,” Mario Cavaleri, chair of the EMA vaccine evaluation team, said, according to Reuters.
“However, we still do not know what causes this reaction.”
“At present the review has not identified any specific risk factors, such as age, gender or a previous medical history of clotting disorders, for these very rare events,” the statement read.
“A causal link with the vaccine is not proven, but is possible and further analysis is continuing.”
The investigation is looking into 44 reports of a rare blood clot in the brain known as cerebral venous sinus thrombosis; 9.2 million people in the European Economic Area have received the vaccine, Reuters reported.
The agency and the World Health Organization maintain that the benefits of AstraZeneca’s vaccine outweigh the risks.
However, France, Germany and the Netherlands have already suspended the use of the vaccine as the investigation continues.
The Netherlands’ medical authority reported that it found blood clots in women between the ages of 25 and 65, according to CNN.
Germany reported that nine of its 31 patients who had developed CVST died, and 29 cases were found in women between the ages of 20 and 63.
Norway reported three deaths among people who developed blood clots and hemorrhaging after receiving the vaccine.
“The Norwegian Medicines Agency believes that there is a probable link with the vaccine, but we need more research to clarify exactly what is triggering this,” the agency said in a statement.
European investigators have floated the idea of an unusual antibody triggered by the vaccine or a possible link to birth control pills, according to Reuters.
EMA Committee for Medicinal Products for Human Use member Armando Genazzani said it was “plausible” that the blood clots were correlated with the AstraZeneca vaccine.
This specific vaccine was based on a modified chimpanzee adenovirus vector, developed at Oxford University.
“Patient safety remains the company’s highest priority,” an AstraZeneca spokesperson told CNN, pointing to medical authorities that continue to recommend the vaccine.