“The Federal Office for Safety in Health Care (BASG) has received two reports in a temporal connection with a vaccination from the same batch of the AstraZeneca vaccine in the district clinic of Zwettl” in Lower Austria province, the health agency said in a statement.

The health agency added that there is “no evidence of a casual relationship with the vaccination” but the remaining stocks of the affected vaccine batch are no longer being used as a “precautionary measure”.

An AstraZeneca spokesman said:

“There have been no confirmed serious adverse events associated with the vaccine,” adding that all batches are subject to strict and rigorous quality controls.

Trials and real-world experience so far suggest the vaccine is safe and effective and it had been approved for use in well over 50 countries, he said.

AstraZeneca also said it was in contact with Austrian authorities and would fully support the investigation.