Risk of blood clots after AstraZeneca Covid jab is ‘small’ and people are three times more likely to die if they aren’t vaccinated
- Researchers in Denmark and Norway looked at nationwide rates of blood clots
- Found slightly increased rates of vein clots and brain clots in AZ-jabbed people
- But stressed the unvaccinated were almost three times more likely to die
The risk of blood clots after the Oxford jab is ‘small’ with people three times more likely to die if they have not had the vaccine, a study has found.
Researchers in Denmark and Norway looked at the nationwide rates of blood clots and related conditions in 280,000 people who had had the jab between February and March this year.
They found slightly increased rates of vein blood clots including clots in the veins of the brain, compared with expected rates in the general population.
However, the researchers stress that the risk of such adverse events was low while those who were unvaccinated were almost three times more likely to die than those who had it.
In a linked editorial, UK scientist Professor Paul Hunter from the University of East Anglia, said the findings showed countries were wrong to pause using the Oxford jab.
He said the results confirmed the benefits ‘far outweigh its risks for most age groups’.
He added: ‘It remains the case that for most age groups, the probability of surviving the year is much greater for people who accept any vaccine when offered than if they decline it.
‘Those countries that delayed their own vaccination programmes at a time of high transmission rates by declining to use available Oxford/AstraZeneca vaccines should know that their decision will have contributed to an increase in the number of avoidable deaths from Covid-19.’
The risk of blood clots after the Oxford jab is ‘small’ with people three times more likely to die if they have not had the vaccine (file)
Using national health records, researchers identified rates of events, such as heart attacks, strokes, deep vein blood clots and bleeding events within 28 days of receiving a first vaccine dose and compared these with expected rates in the general populations of Denmark and Norway.
The team of researchers compared data on 281,264 people – about four fifths were women – and compared this with data from the general population.
The researchers found 59 blood clots in the veins compared with 30 expected in the general population.
This equates to 11 excess blood clotting events per 100,000 vaccinations, including 2.5 additional blood clots in the brain per 100,000 vaccinations.
They found no increase in the rate of arterial clots, such as heart attacks or strokes, according to the findings in the British Medical Journal.
‘Among recipients of ChAdOx1-S (the Oxford /AstraZeneca vaccine) increased rates of venous thromboembolic events, including cerebral venous thrombosis, were observed,’ they said.
‘Absolute risks of events were small and should be interpreted in the context of the benefits of Covid-19 vaccination at both the societal and the individual level.’
Meanwhile, researchers found 15 deaths from all causes after vaccination with the Oxford-AstraZeneca vaccine compared with an expected 44 deaths, showing a lower chance of death after the vaccine.
The vaccine has been linked to rare blood clots and last month, several European countries including Denmark and Norway, went against World Health Organisation advice and halted their rollouts amid concerns over the risks.
The UK medicines regulator, the Medicines and Healthcare products Regulatory Agency, previously concluded that there is a ‘possible link’ between the AstraZeneca jab and extremely rare blood clots.
It said that the benefits of vaccination continue to outweigh any risks, but it has recommended that adults under 30 should be offered an alternative to the vaccine – such as the Pfizer or Moderna jabs.
Officials at the MHRA, which monitors possible side effects of the jabs, have counted 168 cases of blood clots following vaccination with the British jab in the UK so far. More are expected to be announced tomorrow in its weekly report.
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