The European Medicine Agency (EMA) said it remains “fully convinced” the benefits of the Oxford/AstraZeneca Covid-19 vaccine outweigh the risks.
However, it also said that isolated cases of blood clots “are a serious concern and need serious and detailed scientific evaluation”.
Immunisation with the Oxford/AstraZeneca vaccine has currently been suspended in some 13 countries while they seek further clarification on its safety.
No indication shot caused any incidents
The EMA is currently investigating the cases of blood clots in vaccinated people, with the findings expected to be released on Thursday (18 Mar).
Emer Cooke, head of the EU medicines regulator, said there is no indication that the jab had caused any of the incidents, but that the agency was investigating them thoroughly.
Germany, France, Italy and Spain are among the countries to have suspended the vaccine’s use, after a small number of blood clots were reported among people who had recently had the jab.
The Italian prime minister, Mario Draghi, said he spoke with French president Emmanuel Macron, and the two had agreed to resume vaccinations quickly if the vaccine is given the green light via the EMA.
Germany’s health ministry on Tuesday (16 Mar) said it had a “legal obligation” to suspend vaccination, after receiving three more reports of a rare cerebral thrombosis, cerebral sinus venous thrombosis or CSVT, since Friday 12 March.
On Monday (15 Mar), the World Health Organisation (WHO) urged countries to continue using the AstraZeneca vaccine while the investigation was underway.
Why has the UK not suspended the Oxford/AstraZeneca vaccine?
UK Health Secretary, Matt Hancock, has said the Oxford/AstraZeneca vaccine is safe, and has urged people to “get the jab” as soon as they get the opportunity.
The UK’s medicines watchdog, the MHRA, said that evidence “does not suggest” the jab causes blood clots.
Blood clots can occur naturally and are not uncommon.
About 17 million people across the EU and the UK have received a dose of the vaccine, with fewer than 40 cases of blood clots reported as of last week, manufacturer AstraZeneca said.
Mr Hancock stressed that the MHRA, the WHO and the EMA all believed the vaccine was safe.
"We keep the effects of these vaccines under review all the time and we know that the Oxford/AstraZeneca vaccine is saving lives in the UK right now so if you get the call, get the jab," he said.