It is not yet known what is causing thrombosis related with AstraZeneca vaccine

The relation between AstraZeneca’s and Janssen’s vaccines and very uncommon thrombi in those vaccinated patients are being investigated


An article in the Catholic media Church Militants ensures that genetic vaccines make cells “to get attached between them initiating blood coagulation”. For the moment, this is NOT A VERIFIABLE information. It is teure that the relation between AstraZeneca’s and Janssen’s vaccines and very uncommon thrombi in those patients vaccinated with these vaccines are being investigated, but the results are not yet conclusive.

“Genetic vaccines make body cells to produce the spike protein or a piece of it” and cause “the attachment between cells forming a blood clot”

The article is based on an interview with Mike Yeadon, ex-worker at Pfizer, who has been already denied for his inaccuracies about the vaccine against covid-19. Although the explanation given by this physician is “plausible”, according to the first hypotheses from the European Medicines Agency (EMA), it has not yet been possible to confirm which component of the vaccine causes the thrombi and whether the blood clots appear due to the synthesis of the spike protein.

Thrombosis is an aggregation of clots —blood mass formed when blood platelets, proteins and the cells get attached together— in the circulatory system that, due to their movement, block the blood flow, causing a stroke or cerebral or myocardial infarction.

AstraZeneca's and Janssen's vaccines

For the covid-19 vaccines, despite the European Medicines Agency (EMA), sees "clear evidence" relating the cases of blood clots with AstraZeneca injection, it is not yet clear the reason why the drug could trigger them. Nor for Janssen’s case.

In a statement, this European organisation indicates that “a plausible explanation […] of the combination of thrombi and low blood platelets levels could be an immune response, […] similar to that sometimes observed in patients treated with heparin (an anticoagulant)”. What the EMA means is that low platelets levels that have been seen associated with thrombi upon vaccination have their origin in in the immune response itself, and that this has already been seen in patients treated with a drug, heparin, which, paradoxically, is used to prevent blood clots formation. 

This link established by the EMA is very much in line with the conclusions of two studies, one from a German group and another from a Norwegian team, published in early April in New England Journal of Medicine, in which the relation between thrombi and AstraZeneca injection were analysed. The scientists concluded that people who developed these thromboses upon vaccination had higher antibody levels directed against a protein (PF4) produced by platelets, which are fragments of cells that help produce clots in the bloodstream to aid healing wounds. This specially high antibody levels may cause a disproportionate activation of platelets, giving place to the hypercoagulability (more clots and thus more thrombi).

The research have referred to this phenomenon in the studies as a vaccine-induced immune thrombotic thrombocytopenia (although this is a provisional name), and recalls a lot, they explain, to another similar that occurs treating some patients with heparin, and that is known as heparin-induced thrombocytopenia. This syndrome consists of a similar response to that which would occur with the AstraZeneca and Janssen vaccines, which they would activate, giving place, in very rare cases, to a state of hypercoagulability —many more clots than normal — and thus to the famous thrombi.

What causes thrombi?

Having established the clear link between thrombi and vaccines, scientists are currently immersed in finding the mechanisms. And the spike protein, as Yeadon points, does not seem to be the cause: “Indeed, viral vector-based vaccines make the body produce the Spike protein so that it is recognised by the immune system. Nevertheless, this is not the cause behind thrombi”, indicates Adelaida Sarukhan, immunologist and scientific writer at ISGlobal, to Verificat

The scientist reasons that “if the spike protein were the culprit, then this type of thrombi would have been observed with mRNA vaccines (which also code for Spike). And no similar cases have been reported after hundreds of millions of administered vaccines in the US, Europe and Israel”. We will have to wait for new investigations to finally find the real origin of thrombosis.