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A health worker (C) is preparing a dose of the Pfizer-BioNTech Covid-19 vaccine at a vaccination clinic set up inside the Derby Arena in Pride Park in Derby, England, on March 31, 2021.
Oli Scarff / AFP via Getty Images
The risk of getting blood clots is about the same as
Pfizer
and Covid-19 vaccines from Moderna as in
AstraZeneca
according to a study published Thursday.
Researchers at Oxford University, the same university that helped develop a pharmaceutical company
AstraZeneca
vaccine, found that the rare blood clotting known as cerebral venous thrombosis occurred in four out of every million people who received the vaccines from the pharmaceutical company
Pfizer
and biotechnology
Modern.
This compares with five out of every million people after the first dose of the AstraZeneca-Oxford vaccine, they said.
In both cases, the risk of blood clots is much higher in those who contract the Covid-19 virus. The researchers said TVC occurred in 39 of one million patients.
“We have reached two important conclusions. First, Covid-19 significantly increases the risk of CVD, adding to the list of blood clotting problems that cause this infection. Second, the risk of Covid-19 is higher than we see with current vaccines, even for those under 30; something that should be taken into account when considering the balances between the risks and benefits of vaccination, “said Paul Harrison, a professor of psychiatry and head of the translational neurobiology group at Oxford University. .
The study has important implications given how regulators have reacted to concerns about blood clots. In Europe, several countries have limited the use of the AstraZeneca vaccine and the United States is now reviewing the pharmaceutical vaccine
Johnson & Johnson,
which is done through a process similar to that of the AstraZeneca vaccine and which has also triggered blood clot problems.
Both Pfizer and Moderna vaccines are produced with the mRNA process, using the molecules in the cells that control protein production to teach the immune system to produce antibodies to the coronavirus.