Rare risk of blood clotting more for Covid-19 than for vaccines: Oxford study

The risk of rare blood clotting known as cerebral venous thrombosis (CVT) following COVID-19 infection is several times higher than after vaccination, according to a study unveiled Thursday.

The study by researchers at the University of Oxford in the UK counted the number of CVT cases diagnosed within two weeks of being diagnosed with COVID-19, or after the first dose of a vaccine.

They compared them to the calculated incidences of CVT after influenza and to the background level in the general population.

The team found that CVT is more common after COVID-19 than in any of the comparison groups, with 30% of those cases occurring in those under the age of 30.

Compared to current COVID-19 vaccines, this risk is between 8 and 10 times higher, and compared to baseline, about 100 times higher, they said.

“There are concerns about possible associations between vaccines and CVT, leading governments and regulators to restrict the use of certain vaccines,” said Paul Harrison, head of the Translational Neurobiology group at the University of Montreal. ‘Oxford.

“Yet a key question remained unknown: What is the risk of CVT following a diagnosis of COVID-19?” Harrison said.

Researchers noted that COVID-19 dramatically increases the risk of CVT, adding to the list of blood clotting problems this infection causes.

The risk of COVID-19 is higher than that seen with current vaccines, even for those under 30, they said.

This is something that should be taken into account when considering the balance between the risks and benefits of vaccination, according to the researchers.

The researchers noted that it is important that these data be interpreted with caution.

The signals that COVID-19 is linked to CVT, as well as portal vein thrombosis – a clotting disorder of the liver – are clear, and we need to take note, they said.

According to the researchers, an important factor that requires further research is whether COVID-19 and vaccines lead to CVT through the same or different mechanisms.

There may also be underreporting or incorrect coding of CVT in medical records, and therefore uncertainty about the accuracy of the results, they added.

(Only the title and image of this report may have been reworked by Business Standard staff; the rest of the content is automatically generated from a syndicated feed.)

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