Experts probing links between the AstraZeneca coronavirus vaccine and blood clots have found no specific risk factors, including age, but are investigating further, the EU's drug regulator said Wednesday.
The European Medicines Agency (EMA) said however that its safety committee expected to issue an "updated recommendation" on the controversial vaccine after its monthly meeting next week.
Germany on Tuesday became the latest in a series of countries to advise against using the AstraZeneca jab for younger people after rare reports of clotting, despite the EMA saying it is safe.
"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 Amsterdam-based EMA said in a statement.
"A causal link with the vaccine is not proven, but is possible and further analysis is continuing."
The EMA statement came after experts met on Monday to discuss their latest findings on the AstraZeneca vaccine. Their comments will be discussed at the safety committee's meeting next week.
The watchdog reiterated the view it gave in a keenly-anticipated statement on March 18, saying "its benefits in protecting people from Covid-19 with the associated risks of death and hospitalisation outweigh the possible risks."
EMA's chief, Emer Cooke, and the head of the agency's pharmacovigilance and epidemiology department, Peter Arlett, told an online news conference of the cases detected of the rare clotting -- cerebral venous sinus thrombosis (CVST) -- following AstraZeneca vaccine injections.
They said there were 62 cases of CVST worldwide, with 44 of them in the European Economic Area (EEA) comprising the European Union and associated states Norway, Iceland and Liechtenstein.
Cooke added that the EEA figures did not count German cases recorded after March 22, and added that there were 14 fatalities in the region "but not all of them were associated with CVST".
The figures they gave were from 9.2 million AstraZeneca jabs in the EEA region.
Statistics from Brazil, which also uses the AstraZeneca vaccine, were not included.
Cooke said that, while "at this stage of our investigations the link is possible" between rare CVST cases and the AstraZeneca vaccine, more evaluation was needed.
She said that the possible ratio of CVST adverse reactions "for the AZ vaccine based on spontaneous reporting in the EEA, it's 4.8 cases per million".
Comparing to the two other Covid vaccines currently deployed in Europe, she said: "For the BioNTech vaccine based on the same criteria, it was 0.2 cases per million. And for the Moderna vaccine, based on the same criteria, zero cases per million, but that probably reflects that there's a lot less use of Moderna at the moment in Europe."