How a shot clots

I've pretty much 'phoned it in, the last couple days (from space!). I should have been paying attention to the VAXX news... against interest, perhaps.

Sometimes vaccines are associated with auto-immune blood-clots, called Immune Thrombocytopenia and Thrombosis. Birmingham have a pathway: Platelet Factor 4.

With this, the Brummies feel safe in calling it Vaccine-induced IT&T.

The VITT is... scary, for those of us who took the newer shots, like those for CoVID. (I didn't get boosted; I just took Pfizer's original duo.) I propose we deserve to know what we're in for.

Best I can garner, any vaccine makes the body think it's under attack, so creates antibodies. Per the news-release, VITT victims' antibodies had adhered to the PF4 protein (somehow). This creates a big raft of molecules, an "immune complex". Other(?) platelets interpret this as damage and inflame the circulatory system, activating more platelets and - here's the clot. Which clot, then roams around your body to your kidneys or your heart or your brain: Thrombosis.

That summary isn't great for explaining if PF4 was naturally on the antibodies, or if it's on the platelets. Maybe Birmingham didn't know either. Anyway, the 26 October article says that some "c-Mpl" thrombopoietin receptor is on the platelets. Activating a platelet, releases PF4, from the platelet's α-granules. c-Mpl then receives the PF4, which reception activates the "Janus kinase 2" cytosolic-enzyme (a nRTK to be exact; it's involved in T-cells). It looks like platelet-on-platelet action. Anyway all this stuff will stick together.

There already exist drugs as can limit the c-Mpl / PF4 reception. Ruxolitinib, for instance. Normally this is used in treating blood-cancers. It may be that it goes to preventing the cancers, or even the chemotherapy, from inducing immune-complexes and thereby the clots and inflammation.

CoVID is called-out in the release but not in the abstract. I don't know if other vaccines run the same risk. I don't see where the releases point to whether CoVID itself - or any other disease - might also induce IT&T via this pathway. I also don't see if JAK2 has some genetic basis; I presume so.