Pfizer's coronavirus vaccine is just as likely to trigger blood clots as AstraZeneca's, according to a study that has prompted fury among UK Government officials.
Scientists compared rates of thrombosis among more than 1.3million recipients of either jab in Spain.
Both vaccines came with a tiny risk of causing blood clots, with scientists branding their safety profiles 'broadly similar'. Pfizer's jab may even be more likely to trigger the rare blood-clotting complication, the data suggested.
In contrast, the virus itself was eight times more likely to lead to thromboembolism than either jab.
The findings go against an array of research saying the opposite, with health chiefs yet to uncover a link between Pfizer's vaccine and blood clots.
Safety concerns over AstraZeneca's jab first emerged in January, and prompted EU nations to shun the British-made vaccine en masse.
Top scientists insisted the jab was safe and would save thousands of lives, leading to claims the bloc heavyweights were using the vaccine to play post-Brexit politics.
In light of the new findings, one UK Government official accused European leaders of having 'blood on their hands' for trashing the life-saving jab.
The experts noted the difference between the levels of conditions they expected to see (squares) in the general population and compared this to the cases they observed (circles) in people who received a vaccine or who caught Covid. The biggest change was seen among people who caught Covid, with the risk of developing a blood clot in the vein - called venous thromboembolism - jumping from from 62 to 499
Scientists noted that the different ages and health conditions of people who were given the Pfizer and AstraZeneca vaccine may have affected their findings. Of the 945,941 people who received one Pfizer jab (left), the average age was 75, while the 778,534 people fully immunised with Pfizer (middle) were aged 77 on average. But those who got one dose of AstraZeneca had an average age of 61 (right). The study was conducted in Spain, where national guidelines issued in March restricted the use of the Oxford jab to people in their 60s
The unnamed Whitehall insider told Politico: 'We now know what we all suspected is true, they did it out of spite for Britain because of Brexit.
'When the history books are written, they'll say these people were directly responsible for the deaths of thousands in developing countries who won't take AZ because of their anti-vaxx scare stories.'
Covid vaccines have drastically slashed the risk of severe illness, hospitalisation and death from the virus.
Their rapid roll-out has allowed Britain to remove most remaining lockdown-esque restrictions, with ministers confident in how well they work.
But they have been linked to extremely rare complications, with AstraZeneca's jab thought to cause blood clots in 11 in every 100,000 recipients.
Johnson & Johnson's single-dose jab — which works in a very similar way — has also been linked to the same complication.
However, regulators have not spotted any consistent trend between Pfizer's mRNA vaccine and blood clots. Its jab — linked to a very rare kind of heart inflammation — is based on pioneering technology.
Several countries in Europe stopped using
