A senior official for Europe’s drug regulator said there appears to be a “clear link” between the AstraZeneca vaccine and blood clots.

“In my opinion, we can say it now, it is clear there is a link with the vaccine. But we still do not know what causes this reaction,” Marco Cavaleri, chair of the European Medicines Agency’s vaccine evaluation team, told Italy’s Il Messaggero newspaper on Tuesday.

He said that “in the next few hours, we will say that there is a connection, but we still have to understand how this happens.”

The regulator is investigating 44 reports of an extremely rare brain clotting ailment known as cerebral venous sinus thrombosis.

Cavaleri said the agency still won’t be able to provide guidance on what age is safe to receive the vaccine, though a high proportion of the cases occurred among young and middle-aged women.

AstraZeneca and the regulators have repeatedly said the benefits outweigh the risks, noting that the blood clots were rare and occurred out of 9.2 million people in the European Economic Area.

“While the investigation is ongoing, we are still firmly convinced that the benefits of the AstraZeneca vaccine in preventing COVID-19, with its associated risk of hospitalization and death, outweigh the risk of these side effects,” EMA executive director Emer Cooke said last month during a briefing.

Several European countries, including France, Germany and the Netherlands, have paused the use of the vaccine as regulators investigate the reports of blood clots.

With Post wires