There is “no evidence” to support restricting the use of the Oxford/AstraZeneca Covid-19 vaccine in any population, the European Medicines Agency said on Wednesday.
The EU's drug regulating agency said it had found no specific risk factors connecting the vaccine to reports of blood clotting.
But it said: "A causal link with the vaccine is not proven but is possible, and further analysis is continuing."
The watchdog reiterated the view it gave in a keenly anticipated statement on March 18, which said that the "benefits [of the vaccine] in protecting people from Covid-19 with the associated risks of death and hospitalisation outweigh the possible risks".
Some EU countries have restricted access to the vaccine over reports of blood clotting.
On Tuesday, Germany stopped general use of AstraZeneca's product in people under age 60 because of a perceived risk of rare blood clots.
It remains suspended in Denmark and Norway.
The German medicines regulator found 31 cases of a type of rare blood clot among the nearly 2.7 million people who had received the vaccine in Germany.
"According to the current scientific knowledge, there is no evidence that would support restricting the use of this vaccine in any population," said agency chief Emer Cooke.
Ms Cooke said that the assessment was based on 62 cases of unusual blood clots, including 14 deaths, reported to the agency by March 22.
AstraZeneca has renamed its Covid-19 vaccine in Europe as the pharmaceutical company struggles to reassure the public that the drug is safe.
The British-Swedish company said the drug would now be marketed under the new name Vaxzevria but the product itself remains unchanged.
The European medicines regulator approved the new name and has updated its guidance to reflect the change.
