They discover the possible trigger of thrombi after the AstraZeneca vaccine

A team of scientists from the United Kingdom and the United States believe they have discovered the trigger for the development of unusual blood clots in some patients after receiving the Oxford-AstraZeneca coronavirus vaccine.

The team, which publishes its results in the American magazine “Science Advances”, Detected how a protein in the blood is attracted to a key component of the vaccine, which in turn instigates an immune system reaction that, in combination with other factors yet to be determined, can lead to the so-called immune thrombocytopenia ( TPI).

The vaccine ‘Vaxzevria‘, developed by the English University of Oxford with the pharmaceutical company AstraZeneca, has in its composition an adenovirus (specifically, a common cold virus from chimpanzees), unlike other preparations that use “Messenger RNA”Such as those of Pfizer-BioNTech and Moderna.

Previous studies found that people who contract blood clots after receiving the vaccine AstraZeneca they generate unusual antibodies that attack the platelet factor 4 protein in the blood.

According to research released today, adenovirus, which acts as a messenger in the vaccine for Oxford-AstraZeneca, could be linked to the development of thrombi, since everything indicates that its external surface attracts the aforementioned protein.

In some cases, the immune system mistakes platelet factor 4 for the virus and generates antibodies to attack it. As the antibodies bind to the protein, thrombi would develop, the research indicates.

Although the vaccines are injected into muscle, they can sometimes leak into the bloodstream, where the process could start, it is noted.

“ITP only occurs in extremely rare cases because a chain of complex events must occur to trigger this super rare side effect.“Says one of the authors, Alan Parker, from Cardiff University.

“Our data confirm that platelet factor 4 can bind adenoviruses, an important step in triggering the underlying mechanism in ITP. Establishing the whole mechanism could help prevent and treat this condition”He added.

Thrombus formation in a minority of patients has led many governments to limit the administration of the AstraZeneca vaccine, which is nevertheless the cheapest and easiest to transport.

A spokesman for the pharmaceutical company, whose experts participated in the study, pointed out that, “Although the research is not definitive, it offers interesting data“And the company will take them into account in its efforts”to eliminate this rare side effect”.