Trigger of rare blood clots with AstraZeneca and other COVID vaccines found by scientists

understanding rare blood clots caused by some  COVID vaccines – important first to prevention

A collaborative team from the School of Medicine at the University of Cardiff, Wales and a range of US institutions used the UK’s national synchrotron, Diamond Light Source, to help reveal the details of how a protein in the blood is attracted to a key component of Adenovirus based vaccines.  

It is believed this protein kicks off a chain reaction, involving the immune system, that can culminate in extremely rare but dangerous blood clots. The Cardiff team were given emergency government funding to find the answers. In collaboration with scientists in the US and from AstraZeneca, they set out to collect data on the structure of the vaccines and perform computer simulations and related experiments to try and uncover why some of the vaccines based on Adenoviruses were causing blood clots in rare cases.  

Moderna and BioNTech are based on mRNA, whereas AstraZeneca and Johnson & Johnson are based on Adenoviruses. Blood clots have only been associated with vaccines that use Adenoviruses.

Read more on the Diamond website

Image: Crystallisation of ChAdOx1 fibre-knob protein results in 4 copies of the expected trimer per asymmetric unit and reveals side-chain locations. The crystal structure was solved with 12 copies of the monomer in the asymmetric unit, packing to form 3 trimeric biological assemblies. Density was sufficient to provide a complete structure in all copies.

Credit: Image reused from DOI: 10.1126/sciadv.abl8213 under the CC BY 2.0 license.