The possibility of developing thrombosis is smaller after having been administered the COVID-19 vaccination than if one contracts the virus, according to the largest study of the side-effects of the vaccines.

In the framework of the British study, published in the British Medical Journal, comparisons were made between data deriving from 29 million people who had been vaccinated with the first dose of the Pfizer-BioNTech or the AstraZeneca vaccine between December 2020 and April, 2021, and data from two million people who were confirmed COVID-19 cases.

The danger of acquiring venous thromboembolism is nearly 200 times greater if someone contracts COVID-19 (12,614 more confirmed cases per ten million people) than if they receive the AstraZeneca vaccine (just 66 more cases).

As regards arterial thrombosis, there was no additional case for any of the vaccines, yet among people who had contracted COVID-19, 5,000 additional cases per 10 million people.

Hence, people who come down with COVID-19 are 11 times more likely to have a stroke (1,699 more cases per 10 million people than individual who got the Pfizer vax (143 cases).

Epidemiologist Julia Hippisley-Cox told the BBC that the vast majority of patients will be totally well after the jab, and noted that the very rare cases of thrombosis must be put in perspective.

Hippisley-Cox noted that the increased danger of thrombosis occurs in specific and brief periods in the vaccination process – 15 to 20 days after the Pfizer vax for strokes and 18 to 14 days for thrombocytopenia from the Pfizer vax. Once one has contracted COVID-19 the danger period is 28 days after infection.

The results of the study were made public even as many countries, including the UK, decided to limit use of the AstraZeneca vaccine for elderly people due to fears of thrombosis.

Public Health England has expressed the view that vaccines have averted 100,000 deaths in the UK, where 132,000 people have died of COVID-19.

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