Study: Risk of blood clot after coronavirus is eight times higher than after Oxford-AstraZeneca jab

SENFTENBERG, GERMANY - MARCH 03: A nurse holds a vile of the AstraZeneca vaccine against COVID-19 during the inoculation of patients at a private medical practice as part of a pilot project in the state of Brandenburg during the coronavirus pandemic on March 03, 2021 in Senftenberg, Germany. Several German states are allowing vaccinations against COVID-19 to begin in a limited number of private medical practices with the aim of expanding venues that offer the vaccines beyond the current mass vaccination centers. While Germany's vaccination rollout has been hampered by less than anticipated shipments of vaccine, the volume of shipments has begun increasing, leading to higher weekly numbers of vaccinations. (Photo by Sean Gallup/Getty Images)

The risk of developing a blood clot after having COVID-19 is eight times higher than after being given the Oxford-AstraZeneca jab, according to a study by Oxford University.

Cerebral venous thrombosis (CVT) occurred in 39 in a million COVID-19 patients, compared with about five in a million people given the AstraZeneca vaccine.

In the study of over 500,000 coronavirus patients, the risk was reported to be around 100 times higher than normal after infection.

Numerous countries have limited use of the vaccine to certain age groups or paused its rollout – with Denmark even dropping the jab from its vaccination programme permanently – following reports of very rare cases of blood clots.

However, the Oxford study suggested around a third (30 percent) of the CVT reports after COVID-19 infection were in people under 30.

Scientists have said the technology used in the Oxford-AstraZeneca vaccine, harnessing an adenovirus, has been linked to a slightly increased risk of blood clots.

It’s the same explanation for the Johnson& Johnson vaccine, which has been paused in the US after a handful of clotting reports there.

(With input from agencies)