The head of vaccines at the European Medicines Agency (EMA) has said there is a “clear” link between the AstraZeneca Covid-19 vaccination and reports of blood clots in certain people who have received the jab. 

Marco Cavaleri told Italian newspaper Il Messaggero that a brain blockage called CVST was occuring at a higher rate than expected in younger people who have been vaccinated.

“In the next few hours, we will say that there is a connection, but we still have to understand how this happens,” Mr Cavaleri is quoted as saying.

“Among the vaccinated, there are more cases of cerebral thrombosis… among young people than we would expect.”

In response, the EMA’s safety committee said it “has not yet reached a conclusion and the review is currently ongoing” into the purported link between clotting and the injection.

“We will communicate and hold a press briefing as soon as the review is finalised. This is currently expected tomorrow (Wednesday, 7 April) or on Thursday, 8 April.”

According to Cavaleri, the EMA remains unsure as to why the vaccine could be causing the complication.

Cavaleri however insists that the benefits of the vaccine outweigh the risks, and that the jab is safe.

Ireland was one of a large number of countries who overturned their suspension on administering the vaccine amid initial fears that it had led to a higher rate of blood clotting than normal in the general population.

The widespread suspension of the vaccine caused a collapse in confidence across Europe however, with more than half of the German, Italian, French and Spanish citizens polled by YouGov saying they thought the jab was not safe.

Germany then announced a vaccine ban for under 60s on March 30, after its health authorities found 31 cases of CSVT following 2.7 million AstraZeneca inoculations.

Professor Neil Ferguson, whose models were previously proved wrong in terms of Covid-19 mortality rates, said the AstraZeneca vaccine might not be given to young people if a link is demonstrated.

“In terms of the data at the moment, there is increasing evidence that there is a rare risk associated, particularly with the AstraZeneca vaccine,” he told BBC Radio 4.

“But it may be associated at a lower level with other vaccines, of these unusual blood clots with low platelet counts. It appears that risk is age related, it may possibly be — but the data is weaker on this — related to sex.

“And so the older you are, the less the risk is and also the higher the risk is of Covid so the risk-benefit equation really points very much towards being vaccinated.

“I think it becomes slightly more complicated when you get to younger age groups where the risk-benefit equation is more complicated.”