Expert suspects causal link between AstraZeneca jab and rare blood clots

The evidence is shifting towards a causal link between rare blood clots and the Oxford/AstraZeneca Covid-19 vaccine, according to an expert.

The Medicines and Healthcare products Regulatory Agency (MHRA) said it had identified 30 cases of rare blood clot events out of 18.1 million doses of the jab administered up to and including March 24.

There have been seven deaths among the 30 cases.

But the regulator said the benefits of the vaccine in preventing coronavirus outweigh any risks and it urged the public to continue coming forward for the jab.

It did not disclose any information about the seven people who died such as their ages or health conditions.

The 30 cases include 22 reports of cerebral venous sinus thrombosis (CVST) and eight of other thrombosis events with low platelets.

CVST clots stop blood draining from the brain properly.

Professor Paul Hunter, a medical microbiologist at the University of East Anglia, told the BBC Radio 4 Today programme: “It is not uncommon to get clusters of rare events purely by chance.

“But once you find that cluster in one population and it then crops up in another – such as previously in the German and now in the English – then I think the chances of that being a random association is very, very low.

“Clearly more work needs to be done, but I think the evidence is shifting more towards it being causally related at the moment.”

However he said the risks of taking the AstraZeneca vaccine are still far outweighed by the risks of not getting the jab.

“The chance of dying if you don’t have the vaccine is many times greater than the risk of dying from CVT (cerebral venous thrombosis) after the AstraZeneca vaccine, even if it does turn out, as I suspect it will, that this link is causal,” he said.

Germany is suspending use of the AstraZeneca vaccine for people aged under 60 due to fears of a link with rare blood clots.

On Friday, the Dutch government also said it would temporarily halt AstraZeneca jabs for people under 60, after it received five reports of blood clots with low blood plate counts following vaccinations.

But the head of the European Medicines Agency (EMA) has said there is “no evidence” to support restricting the use of the AstraZeneca vaccine in any population.

The agency said a causal link between unusual blood clots in people who have had the vaccine is “not proven, but is possible”, also adding that the benefits of the vaccine outweigh the risks of side effects.

That view is echoed by the World Health Organisation (WHO), which has urged countries to continue using the jab.

Dr June Raine, MHRA chief executive, said: “The benefits of Covid-19 vaccine AstraZeneca in preventing Covid-19 infection and its complications continue to outweigh any risks and the public should continue to get their vaccine when invited to do so.

“As published in our most recent weekly summary of yellow card reporting for Covid-19 vaccines, up to and including March 24 we had received 22 reports of CVST and eight reports of other thrombosis events with low platelets, out of a total of 18.1 million doses of Covid-19 vaccine AstraZeneca given by that date.

“There were no reports for the Pfizer/BioNTech vaccine. Our thorough review into these reports is ongoing.

“We are asking healthcare professionals to report any cases they suspect to be linked with Covid-19 vaccination via the coronavirus yellow card website.”