Health authorities in Denmark, Norway and Iceland suspended the use of AstraZeneca's COVID-19 vaccine shots on Thursday, following reports of the formation of blood clots in some people who had received the vaccine.
The announcement comes after Austria stopped using a batch of AstraZeneca shots while investigating a death from coagulation disorders and an illness from a pulmonary embolism.
Still, the European medicine regulator said the vaccine's benefits outweighed the risks and could continue to be administered.
Denmark suspended the AstraZeneca shots for two weeks after a 60-year-old woman, who was given a shot from the same batch used in Austria, formed a blood clot and died.
It said the suspension was also prompted by reports "of possible serious side effects" from other European countries.
Some health experts said there was little evidence to suggest the AstraZeneca vaccine should not be administered. One expert told Reuters it's extremely difficult "distinguishing a causal effect from a coincidence."
AstraZeneca told Reuters in a written statement that the safety of its vaccine had been extensively studied in human trials and peer-reviewed data confirmed it was generally well tolerated.
The drugmaker said this week there had been "no confirmed serious adverse events associated with the vaccine," and said it was in contact with Austrian authorities about the death and would fully support their investigation.