Scientists downplay clotting risk saying vast majority will be 'absolutely fine' after Covid jab

Researchers compared the AstraZeneca and Pfizer vaccines with risks from Covid-19 on such a large scale. File photo

The vast majority of people will be "absolutely fine" after their coronavirus vaccine, according to new research showing the increased risk of blood clots after a jab is much lower than with Covid-19.

Researchers compared the AstraZeneca and Pfizer vaccines with risks from Covid-19 on such a large scale.

They looked at more than 29 million people aged 16 or older who had a first dose of either vaccine in England between December and April.

Their findings suggest the risk of thrombocytopenia, a condition where the patient has a low count of cells, known as platelets, that help the blood clot, in someone with coronavirus is almost nine times higher than in someone who has had one dose of the AstraZeneca jab.

Professor Aziz Sheikh, one of those involved in the study, said the increased risk of thrombocytopenia seen in their work is similar to other commonly used vaccines such as the flu jab.

They estimated that in 10 million people vaccinated with the AstraZeneca jab, there would be 107 additional cases of thrombocytopenia in the 28 days post-vaccination, compared with 934 in people with the virus.

The scientists found an association between those vaccinated with the Pfizer jab and an increased risk of stroke, but the risk was more than 10 times greater in those with the virus.

There were an estimated 143 extra cases of ischaemic stroke per 10 million people with Pfizer, compared with 1,699 cases in those with Covid-19.

The paper, published in The British Medical Journal, said that per 10 million people jabbed with AstraZeneca, there were an estimated seven additional cases of CVST, while there were 20 in people with Covid-19.

For blood clotting in a vein (venous thromboembolism) they estimated some 66 excess events per 10 million people vaccinated with AstraZeneca, compared with around 12,614 excess events in those with Covid.