A team of doctors at Medical University of Vienna treated a 62-year-old woman suffering from a rare thrombosis observed in people following AstraZeneca vaccination against Covid-19.The condition medically referred to as VITT (vaccine-induced thrombotic thrombocytopenia) is associated with a low thrombocyte (blood platelet) count and a clotting disorder. It occurs at unusual sites in the body.Following vaccination, the patient developed vaccine-induced prothrombotic immune thrombocytopenia (VIPIT).The patient was admitted at the Department of Medicine at the University with a low platelet count and low fibrinogen levels. Fibrinogen is a protein that plays a major role in blood clotting. Her condition showed all signs of the beginning of thrombosis.The doctors quickly treated the patient with a high dose of intravenous immunoglobulin concentrates, cortisone and specific anticoagulants, so that thrombosis was prevented.
Immunoglobulin concentrates contain antibodies that can block the misdirected immune response. The usual heparin preparations must not be used to prevent clotting, since they can trigger thrombosis, or aggravate it. The patient responded immediately to the treatment."In this case we were able to describe, for the first time, the efficacy of a potentially life-saving treatment strategy for vaccine-induced thrombosis," said coagulation specialist Paul Knobl, at the varsity.The findings have been published in the Journal of Thrombosis and Haemostasis. While the findings support the current treatment recommendations, they also show that prompt diagnosis and immediate initiation of treatment are necessary in order to prevent a life-threatening thrombosis.VITT is most probably caused by a defective immune response, whereby thrombocyte-activating antibodies are produced resulting in thrombocytopenia (low platelet count) and thrombosis. The mortality rate in VITT is high (40-50 per cent) and the syndrome requires immediate and appropriate treatment.Rare blood clotting following AstraZeneca vaccination have been reported from various countries including India, UK and the US. However, studies have shown the risks far outweigh the benefits provided by the vaccinations.