Risk of blood clots MUCH higher from Covid infection than AstraZeneca or Pfizer jabs
COVID jabs are no more likely to cause blood clots than the flu vaccine – and much less likely to than catching coronavirus, scientists say.
Under-40s were stopped from having the AstraZeneca jab in May because of the clotting scare – and the cases have stopped happening since.
A study led by Oxford University found vaccines do increase the risk, but it is a small rise and the danger is “substantially higher” for people who get sick with the virus instead.
Professor Carol Coupland explained that if 10million people got the AstraZeneca jab, it could cause blood clots in the veins of 66 more people than average.
By comparison, if the same number of people caught Covid it could cause more than 12,500 extra clots.
The same pattern was also seen for a condition called thrombocytopenia, which leaves people with unusually low blood platelets.
Prof Aziz Sheikh, from the University of Edinburgh, said: “These are similar orders of risk as have been seen with other vaccines.
“Thrombocytopenia is a well-described risk in the context of other vaccines that are commonly used in the UK – MMR and influenza are known to increase the risk.”
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The study, published in the British Medical Journal, added: “The risks of most of these events were substantially higher after coronavirus infection than after vaccination.”
Dr Mike Tildesley, a member of the Scientific Pandemic Influenza Group on Modelling (Spi-M) which advises the Government, said he hoped a new large-scale study showing that risks of clots shortly after jabs are much lower compared to in people who get coronavirus "maintains the trust in the vaccines going forward".
The research findings were published a day after an inquest heard that BBC radio presenter Lisa Shaw, 44, died due to complications of the AstraZeneca vaccination.
Dr Tildesley told BBC Breakfast: "I think it is about putting those risks into context. There are always going to be the tragic cases like Lisa unfortunately, but it still doesn't mean that actually the risks of taking the vaccine are high - it is still so much more risky to catch Covid and develop a blood clot via that route."
And Professor Julia Hippisley-Cox, professor of clinical epidemiology and general practice at the University of Oxford, stressed the "vast majority of patients will be absolutely fine" following their coronavirus vaccination.
"It's very sad, and condolences to the family of Lisa," Prof Hippisley-Cox told BBC Radio 4's Today programme.
"But to put it in context, these are very rare cases, and the vast majority of patients will be absolutely fine with these vaccines."
Blood clots happen for a wide range of reasons, with around 3,000 people a month in the UK suffering them.
Thrombosis UK said taking the contraceptive pill makes you two or three times more likely to develop a clot.
Being hospitalised for any reason increases risk tenfold, while 60 per cent of major orthopaedic surgery patients suffer a clot.