Scientists believe they've discovered "the trigger" for exceedingly uncommon blood clots following the Oxford-AstraZeneca Covid vaccination.

The team, based in Cardiff and the United States, has demonstrated in minute detail how a protein in the blood is drawn to a vaccine component.

They believe that this sets off a chain reaction that involves the immune system and can result in deadly clots.

About a million people are expected to have been rescued from Covid thanks to the vaccination.

Concerns about uncommon blood clots, on the other hand, have affected how the vaccine has been used across the world, notably in the United Kingdom, where an alternative is being provided to those under the age of 40.

It also sparked a scientific investigation into what was going on and if it might be avoided. To uncover the answers, the Cardiff team was awarded emergency government funds.

 

After the team's initial findings were published, AstraZeneca's scientists joined the study endeavor.

Clots are more likely to arise as a result of a Covid infection than the vaccination, according to an AstraZeneca representative, and the whole explanation for why they occur has yet to be determined. 

"Although the research is not definitive, it offers interesting insights and AstraZeneca is exploring ways to leverage these findings as part of our efforts to remove this extremely rare side effect," she added.

For the researchers looking into the uncommon blood clots, there were two early clues:

• The greater risk of clots was seen only with some of the vaccine technologies.
• People with clots had unusual antibodies that were attacking a protein in their blood called platelet factor four.

To train the immune system, all vaccinations used in the UK attempt to transfer a fragment of the Covid-genetic virus's code into the body.

Some of the packages coded within fat spheres, while the AstraZeneca one employed an adenovirus (a common cold virus found in chimps) as its tiny messenger.

The adenovirus was assumed to be associated with the uncommon clots that develop in some persons, according to the researchers. They utilized a method called cryo-electron microscopy to acquire molecular-level photographs of the adenovirus.

Their study, published in the journal Science Advances, reveals the outer surface of the adenovirus attracts the platelet factor four protein to it like a magnet.