'Clear link' between blood clots and AstraZeneca jab, says senior EMA regulator
The benefits of the shot still outweigh the risks, he said.
But many scientists say there is no definitive evidence and it is not clear whether or why AstraZeneca's vaccine would cause an issue not shared by other vaccines that target a similar part of the coronavirus.
Boris Johnson said getting vaccinated was "the key thing" and the regulator's advice was to keep giving the jab.
The European Medicines Agency's (EMA) safety committee has been reviewing very rare cases of unusual blood clots in people vaccinated with the Oxford-AstraZeneca vaccine.
She noted that out of the 346,900 doses of this vaccine that have been administered in Greece, only one "probable" case of the syndrome has been recorded.
"The U.K. needs to be on high alert as it starts using the vaccine in younger people", Sam Fazeli, an analyst with Bloomberg Intelligence, wrote in a report.
In response to Cavaleri's comments, the Amsterdam-based EMA said in a statement on Tuesday: "EMA's Pharmacovigilance Risk Assessment Committee (PRAC) has not yet reached a conclusion and the review (of any possible link) is now ongoing".
But when it comes to the EU's slow vaccine rollout, Breton blamed the AstraZeneca laboratory.
It said that the committee had "not yet reached a conclusion and the review is now ongoing", but it is expected to announce findings later this week. "But we still do not know what causes this reaction", Cavaleri told Italy's Il Messaggero newspaper in an interview.
The regulator has consistently said the benefits outweigh the risks as it investigates 44 reports of an extremely rare brain clotting ailment known as cerebral venous sinus thrombosis (CVST) out of 9.2 million people in the European Economic Area who have received the AstraZeneca vaccine.
Britain - where AstraZeneca has been administered more than in any other country - registered 30 cases as of Saturday, including seven fatalities, across a total of 18.1 million doses.
The agency said that a "causal link with the vaccine is not proven but is possible, and further analysis is continuing".
Theodoridou urged the public to look at the daily number of deaths due to Covid-19, and "to weigh the serious, near-immediate risk of the disease against the very distant risk of the vaccine having a possible rare side effect".
So far in Ireland, over 203,000 doses of the AstraZeneca vaccine have now been administered.