The Speaker
Sunday, 21 July 2024 – 09:27

Oxford-AstraZeneca blood clot risk “similar” to that of Pfizer-BioNTech

A Spanish study has found that the blood clot risk from the Oxford-AstraZeneza vaccine is “similar” to the rate amongst other vaccines, namely the Pfizer-BioNTech shot.

The study compared live data – from those who have received the vaccine – from over 1.3 million people in the Spanish region of Catalonia. The study said: “similar safety profiles were seen for both vaccines.”

Most significant, the study concluded that the rate of blood clots amongst those who had been infected with Coronavirus was significantly higher than those amongst the receivers of either vaccine. It suggests that the risk of blood clots is higher for those who are unvaccinated and catch Covid-19.

The study suggested that the rates of blood clots were eight times higher in people who had been infected by Covid-19. It also found the risk of blood clots after receiving the vaccine were 1.3% higher than in those who had not been vaccinated.

That does not mean that the risk of getting a blood clot after either vaccine is 1.3%, the risk remains firmly below 0.0001% according to data from the European Medicines Agency.

The data also found that the risk increased after the first dose of either vaccine, but decreased after the second dose had been received.

Researchers also concluded that the risk of blood clots in the arteries was close to, or often even lower than, the number of blood clotting events that would be expected in a normal, unvaccinated control group.

“In general, rates of thrombosis after vaccination with a first dose of [AstraZeneca] were similar to those seen after a first dose of [Pfizer/BioNTech], although with fewer study participants having received this vaccine, there was greater uncertainty around estimates.”

According to the study, around two-thirds of participants had the Pfizer/BioNTech vaccine, whereas one-third had the Oxford-AstraZeneca.

A different study, across a wider area of the EU, found that after both doses of the vaccine had been received, the risk of blood clots remained practically the same as those who were not vaccinated; the risk – albeit small – appears to be primarily during the gap between doses.

The second study found that for every million people who received the first dose, there were 8.1 reports of blood clots. The study analysed data from a total of 49.23 million people who received the vaccine in the EU, the European Economic Area and the U.K. by the end of April 2021.

After the second dose, there were 2.3 cases out of every million people that reported blood clotting issues, roughly similar to the general population’s occurrence.

This comes in the days after AstraZeneca and many of its researchers spoke of their dismay at the political reaction to their vaccine in the European Union, with a UK government spokesperson allegedly saying that leaders have “blood on their hands” for fearmongering about the Oxford-AstraZeneca vaccine.

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