“But we do take them seriously and investigate,” he said.

Professor Kelly said the Australian health authorities had spoken with their European counterparts overnight,including the EMA,UK and Danish authorities.

“The action taken by several European countries is a precautionary measure so that a full investigation can be rapidly conducted,” he said. He stressed that more than 11 million people vaccinated in the UK without evidence of an increase in blood clots.

Iceland suspended shots with the vaccine as it awaited the results of an investigation by the EMA. Italy said it would suspend use of an AstraZeneca batch different to the one used in Austria.
But several other European countries,including Sweden,France and Spain have continued using their AstraZeneca vaccines,deeming there to be no indication that the vaccines caused the blood clots.

The batch of 1 million doses went to 17 EU countries.

Stephen Evans,professor of pharmacoepidemiology at the London School of Hygiene&Tropical Medicine said the response from Denmark,Iceland and Norway was “super-cautious” based isolated reports.

“The problem with spontaneous reports of suspected adverse reactions to a vaccine are the enormous difficulty of distinguishing a causal effect from a coincidence,” he said,adding that the COVID-19 disease was very strongly associated with blood clotting.

AstraZeneca on Thursday said in a written statement that the safety of its vaccine had been extensively studied in human trials and peer-reviewed data had confirmed the vaccine was generally well tolerated.