Australia is investigating whether a blood clotting case recorded on Friday is related to the AstraZeneca coronavirus vaccine, a health official said, raising concern in a nation where most people are expected to receive the drugmaker's shot.
There have been seven deaths among the 30 cases.
The MHRA previously said there had been 30 cases of rare blood clot events reported out of the 18.1 million AstraZeneca/Oxford vaccine doses administered in Britain.
But, he said, "The key thing to remember is how rare these brain clots are, and how powerful the proven benefit of vaccination is against COVID". However, the EMA has recommended that the vaccine should carry a warning about possible links to severe blood clots so that health practitioners can be on the lookout for it.
AstraZeneca Plc said the review of safety data of people vaccinated with its Covid-19 vaccine has shown no evidence of an increased risk of blood clots.
Several European countries temporarily suspended their use of the vaccine after a small number of people developed blood clots, but most restarted after the EU medicines regulator concluded it was safe and effective.
Nevertheless, the relatively minor risk of rare cases of blood clotting was lesser than the risk of Covid-19 outbreaks, Mr Kidd said.
America's leading expert on infectious diseases, Dr Anthony Fauci, has said the United States may not need the AstraZeneca vaccine against coronavirus even if the country's Food and Drug Administration (FDA) authorises its use.
The Australian Technical Advisory Group on Immunisation and the TGA have been closely monitoring reports overseas of blood clotting within four to 20 days of receiving the AstraZeneca vaccine, Prof Kidd says, including the condition known as "central venous sinus thrombosis".
This view is echoed by the World Health Organisation (WHO), which has urged countries to continue using the jab.
Pharmacovigilance Centre Lareb, a Dutch organization that monitors vaccine side effects, said it had received five reports of blood clots andlow blood platelet counts following vaccinations.
"Because when you see either deaths or unlikely adverse events that you wouldn't anticipate or you didn't see in the trials it's reasonable for regulators to look at this".