EU regulators probe safety of AstraZeneca vaccine batch after blood clot reports

European safety regulators have launched an investigation into the safety of a batch of the Oxford University/AstraZeneca COVID-19 vaccine, as countries including Denmark suspended its use as a precaution following reports of blood clots.

Initial findings showed no issue with the shots suspended by Austrian authorities after a person was diagnosed with severe blood clotting and died 10 days after vaccination.

Another was hospitalised with pulmonary embolism after being vaccinated and is now recovering after being vaccinated.

In a statement, the European Medicines Agency said two other reports of blood clotting events had been received for this batch.

However, a preliminary review by the EMA’s safety committee said there is “no indication that the vaccination has caused these conditions, which are not listed as side effects with this vaccine.”

Batch ABV5300 was delivered to 17 EU countries and comprises 1 million doses of the vaccine.

Several other European countries including Denmark, Estonia, Lithuania, Luxembourg and Latvia, also subsequently suspended this batch as a precautionary measure, while the investigation is ongoing.

The Danish Health and Medicines Authority has suspended the use of the vaccine for at least 14 days while investigations are carried out.

Søren Brostrøm, director of the National Board of Health said: "We are in the middle of the largest and most important vaccination rollout in Danish history.

"And right now we need all the vaccines we can get. Therefore, putting one of the vaccines on pause is not an easy decision.”

He added that the country has not opted out of using the vaccine and is putting its use on hold.

“There is good evidence that the vaccine is both safe and effective,” he said.

The EMA said a quality defect is considered unlikely at this stage, the batch quality is being investigated by the EMA’s experts.

The EMA said its investigation is ongoing and its Pharmacovigilance Risk Assessment Committee (PRAC) is investigating the cases reported with the batch as well as all other cases of thromboembolic events, and other conditions related to blood clots, reported after vaccinations.

The information available so far indicates that the number of thromboembolic events in vaccinated people is no higher than that seen in the general population.