Bulgaria on Friday temporary halted inoculations with the AstraZeneca COVID-19 vaccine until the European medicine regulator produces a written statement dispelling all doubts about the vaccine's safety.
"Until all doubts are dispelled and as long as the experts do not give guarantees that it does not pose a risk to the people, we are halting the inoculations with this vaccine," Prime Minister Boyko Borissov said in a statement.
Bulgaria joined Denmark, Norway and Iceland, who had temporary suspended the rollout of the AstraZeneca vaccine amid reports that blood clots had formed in some who had received the shot.
The European Medicines Agency (EMA) backed the use of the vaccine on Thursday, saying its benefits outweighed its risks and could continue to be administered.
AstraZeneca said on Thursday it had found no evidence of an increased risk of pulmonary embolism or deep vein thrombosis - marked by the formation of blood clots - in safety data of more than 10 million records, even when considering subgroups based on age, gender, production batch or country of use.
On Friday, Germany said it would continue to administer the AstraZeneca vaccine and France said it has shown great efficacy.