Concerns over the clotting led more than a dozen European countries to suspend use of the vaccine over the past week, even though the company and the international bodies said there was no indication the shots caused the clotting and recommended continuing inoculations.
The ruling came after the head of the EMA earlier this week said it would consider a range of actions, including the addition of extra warnings to the vaccine.
“We are worried that there may be an effect on the trust of the vaccines,” Executive Director Emer Cooke said. “But our job is to make sure that the products that we authorise are safe and we can be trusted by the European citizens.”
Blood clots have been reported in at least 37 people, and at least four deaths among them have been recorded, out of the 17 million who have received at least one dose of the AstraZeneca vaccine in EU member states.
Both the EMA and the World Health Organisation have said the benefits of immunisation far outweighed any potentially small risk. Meanwhile AstraZeneca said that it found no evidence of any increased risk of blood clots.
Ahead of the EMA’s announcement, the UK drug regulatory agency said a detailed review into five rare blood clots among the 11 million people who got the AstraZeneca shot found that “a causal association with the vaccine was not established.”
The MHRA said it was continuing to investigate and that “as a precautionary measure we would advise anyone with a headache that lasts for more than four days after vaccination, or bruising beyond the site of vaccination after a few days, to seek medical attention.”
The advice was similar to that issued by other European regulators earlier this week.
The pause in vaccinations using the shot comes as tens of thousands of new daily cases have prompted new lockdown measures in Italy, caused hospitalisations in France to spike and led German officials to announce a third surge of Covid-19 has begun.
In Britain, which has raced ahead in vaccinating its most vulnerable, officials have said the number of people getting their first dose will be “significantly constrained” in April because of a reduction in the vaccine supply to the country.
Figures from the European Centers for Disease Prevention and Control this week show there are about seven million unused doses of the AstraZeneca across the 27-nation bloc.