Pfizer, Moderna vaccines can also cause ultra-rare blood clots, study claims

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The risk of getting blood clots is about the same

Pfizer

‘s and Moderna’s Covid-19 vaccines as in

AstraZeneca

s, according to an investigation released Thursday.

Researchers from the University of Oxford, the same university that contributed to the development of a pharmaceutical company

AstraZeneca

vaccine, found that the rare blood clotting known as cerebral vein thrombosis occurred in four out of every million people who received the vaccines from a pharmaceutical company

Pfizer

and biotech

Modern

That’s comparable to five in a million people after the first dose of the AstraZeneca-Oxford vaccine, they said.

In either case, the risk of blood clots is much higher in those who contract the Covid-19 virus. CVT occurred in 39 out of a million patients, the researchers said.

“We have come to two important conclusions. First, Covid-19 significantly increases the risk of CVT, adding to the list of blood clotting problems that this infection causes. Second, the risk of Covid-19 is higher than we see with current vaccines, even for people under 30; something to take into account when balancing the risks and benefits of vaccination, ”said Paul Harrison, professor of psychiatry and head of the translational neurobiology group at the University of Oxford.

The study has big implications given how regulators have responded to concerns about blood clots. In Europe, several countries have restricted the use of AstraZeneca vaccines, and the US is now reviewing the pharmaceutical industry’s vaccine

Johnson & Johnson

which was created using a similar process to the AstraZeneca vaccine and has also raised concerns about blood clots.

Both the Pfizer and Moderna vaccines are produced by the mRNA process, which uses the molecules in cells that control protein production to teach the immune system to make coronavirus-fighting antibodies.