Thursday, May 27, 2021

German scientists identify possible cause of vaccine blood clots

 Scientists in Germany believe they have discovered why the Oxford-AstraZeneca and Johnson & Johnson coronavirus vaccines cause potentially fatal blood clots in rare cases, and claim the issue can be fixed with a minor adjustment.

The Telegraph

The authors of a new study claim their findings show that it is not the key component of the vaccines that cause the clotting, but a separate vector virus that is used to deliver them to the body.

Both the AstraZeneca and Johnson & Johnson jabs use a modified adenovirus, similar to the common cold virus, to deliver the spike protein of SarsCov2, the virus that causes Covid-19.

The scientists claim the delivery mechanism means the spike protein is sent into the cell nucleus rather than the cellular fluid, where the virus usually generates proteins.

In rare cases, they argue, parts of the spike protein can splice inside the nucleus, creating mutant versions which do not bind to the cell membrane where immunisation takes place, but are secreted into the body, where they can cause blood clots.

Dangerous clots in the brain have been recorded in 309 cases out of 33 million people who have received the AstraZeneca vaccine in the UK, and there have been 56 deaths.

“The adenovirus life cycle includes ... the entry of the adenoviral DNA into the nucleus, and subsequently gene transcription by the host transcription machinery,” the scientists claimed in a preprint of the study released this week.

“And exactly here lies the problem: the viral piece of DNA… is not optimised to be transcribed inside the nucleus.”

But Prof Rolf Marschalek of Frankfurt’s Goethe University, the leader of the study, claims the issue can be easily fixed by modifying the spike protein to prevent it splitting.

“With the data we have in our hands we can tell the companies how to mutate these sequences, coding for the spike protein in a way that prevents unintended splice reactions,” Prof Marsalek told the Financial Times.

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