Scientists tie platelet factor 4 to AstraZeneca COVID vaccine-related clotsUK researchers have uncovered the novel mechanism behind rare abnormal blood clotting seen in some AstraZeneca/Oxford vaccine recipients, according to a study today in the New England Journal of Medicine.The study involved clinical and lab evaluation of 23 previously healthy patients who experienced blood clots and thrombocytopenia (low platelet counts) 6 to 24 days after receiving the first dose of the AstraZeneca vaccine.
Most clots were cerebral venous thrombosis, while some were arterial thrombosis and venous thromboembolisms such as pulmonary embolisms.Twenty-one patients had antibodies for clot-promoting platelet factor 4 (PF4) on enzyme-linked immunosorbent