Interesting figures at the end of that article, giving numbers for vaccines and then a background rate:Herainestold wrote: ↑Tue Apr 13, 2021 10:38 pmIf it is related to an adenovirus then it should occur with the Sputnik V vaccine..Still, Paul Offit, the director of the Vaccine Education Center at Children’s Hospital of Philadelphia and a veteran of discussions about vaccine safety, rattled off a list of questions even before the news about the J&J vaccine broke. Why, he asked, would a vaccine lead to the production of antibodies against platelet factor 4? He emphasized that even when the FDA authorized the vaccine, the plan had been to carefully monitor for cases of thromboses. Offit sits on a key FDA committee involved in reviewing vaccine data.
“What you really would love to know,” Offit said, “is what is causing the immune response to platelet factor 4?”
Is some part of the adenovirus mimicking platelet factor 4? If so, would that same mimicry occur with other adenoviruses? There’s no clear answer. But Offit suspects it’s a class-wide problem, meaning the same phenomenon associated with AstraZeneca’s vaccine is associated with Johnson & Johnson’s.
“There is going to be something about the adenovirus — whether it’s adenoviral DNA or an adenovirus protein — that complexes with platelet factor 4. So that will be determined, I suspect soon.”
https://www.statnews.com/2021/04/13/res ... ome-clues/
Pfizer -35 serious blood clots in 54m doses (world wide? EU? not sure)
Moderna - 5 serious blood clots in 4m doses (EU)
J&J - 4 blood clots with low platelet levels* in 4.5million (world wide?)
And then background: 169 cases of CVST and 53 similar clots in abdominal vessels in 34m people. Over what time frame it doesn't say.
* Note it doesn't say 'with low platelet levels' for the Pfizer & Moderna stats, so I'm assuming those might be more run of the mill clotting events & so more likely not related to the vaccination.
A google of adenovirus & low platelet levels brought me to this paper about using adenovirus to deliver gene therapy: Adenovirus-Platelet Interaction in Blood Causes Virus Sequestration to the Reticuloendothelial System of the Liver
If I skim-read it right they found the adenovirus binds to platelets, activates them, and then the resulting platelet/virus aggregates are cleared from the blood. And it says (my bold):
So if clots & low platelet levels are rare complications of adenovirus infection, that might explain it happening after vaccines based on adenovirus. (And if that complication of infection was known, why the countraindications for AZ were blood thinners & any bleeding/bruising problems.)Although a role for platelets in the removal of blood-borne infectious agents has not been proposed, it is known that many viral infections (including those caused by hepatitis C virus, human immunodeficiency virus, mumps virus, Dengue virus, human T-cell leukemia virus, human cytomegalovirus, severe acute respiratory syndrome virus, swine fever virus, hantavirus, parvovirus B19, influenza virus, and Epstein-Barr virus) induce thrombocytopenia, and that viruses are frequent contaminants of platelet concentrates used for transfusion. Platelet activation, aggregation, and subsequent degradation in the reticuloendothelial system have been seen during infections with swine fever virus. For Ad, studies with animal models and humans describe decreases in platelet number and circulation time, indicating that the platelet-mediated pathway of Ad clearance that we discovered in our mouse model is also relevant for humans. This is supported by observations of thrombotic thrombocytopenic purpura or deep venous thrombosis in patients with disseminated adenoviral infections. Furthermore, it is feasible that removal of activated/pathogen-loaded platelets could involve phagocytosis by tissue macrophages, as has been described for idiopathic thrombocytopenic purpura
I'll be relieved if it's to do with the adenovirus, tbh. My immediate thought was it was the spike protein, as Covid itself causes thrombosis. If it's just the vector, we can switch to a different one or stick to mRNA vaccines.