Thromboembolic events following COVID-19 vaccination

Postgraduate Thesis uoadl:3216229 72 Read counter

Unit:
Κατεύθυνση Θρόμβωση-Αιμορραγία-Ιατρική των μεταγγίσεων
Library of the School of Health Sciences
Deposit date:
2022-04-29
Year:
2022
Author:
Vasilopoulou Mavra
Supervisors info:
Παναγιωτακόπουλος Γεώργιος, Επίκουρος Καθηγητής, Ιατρική Σχολή, Πανεπιστήμιο Πατρών
Πολίτου Μαριάννα, Καθηγήτρια, Ιατρική Σχολή, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Τραυλού Ωραιάνθη, Ομότιμη Καθηγήτρια, Ιατρική Σχολή, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Original Title:
Θρομβοεμβολικά επεισόδια έπειτα από εμβολιασμό έναντι της νόσου COVID-19
Languages:
Greek
Translated title:
Thromboembolic events following COVID-19 vaccination
Summary:
Since 1798, when the first smallpox vaccine was developed, until now, vaccination has been an integral part of the battle against infectious diseases, contributing to their eradication and the prevention of serious disease and its complications. The evolving COVID-19 pandemic, attributed to SARS-CoV-2 virus with its increased transmissibility, morbidity, mortality and the arising new mutations, as well as its multidimensional social and economic effects worldwide, constitute the most typical example of the imperative need for development of an effective vaccine in modern times. Within months, vaccines based on new technologies, such as mRNA and viral-vectored, have been developed, approved and are now being administered worldwide. Soon after their release, however, reported thromboembolic events were associated with the administration of both vaccine types, but primarily with adenoviral-vector (ADV) vaccines; the investigation of the resulting safety signal revealed a new clinical entity: Vaccine-induced immune thrombotic thrombocytopenia (VITT). VITT is characterized by thrombocytopenia and thrombosis in usual and unusual sites, 5-30 days after vaccination with ADV vaccine, with cerebral venous sinus thrombosis being the most frequent thrombotic event. A higher occurrence frequency is observed in younger individuals, but no other predisposing factors have been clearly identified. The pathophysiological mechanism is similar to that of spontaneous heparin-induced thrombocytopenia, with presence of heparin-independent anti-PF4 antibodies that activate platelets. Many assumptions are made for their triggering factor, with current evidence implicating adenoviruses and other vaccine components, as well as their interactions with the immune system of vaccinated individuals. VITT diagnosis is based on clinical and laboratory criteria, while treatment includes, in addition to anticoagulant therapy, immunomodulatory drugs and plasmapheresis for severe or refractory cases. The initially increased mortality of VITT cases decreased over time, due to the evolution and dissemination of medical knowledge. However, many questions remain unanswered and a broad field of research is unfolding on the occasion of VITT, as adenoviral vectors are tested in various treatments, while the development of safe and effective vaccines, not only against SARS-CoV-2, but also against any other emerging pathogen, is and will be a primary goal and necessity.
*Literature review was conducted until January 2022.
Main subject category:
Health Sciences
Keywords:
Thromboembolic events, COVID-19, mRNA vaccines, Viral-vectored vaccines, VITT
Index:
No
Number of index pages:
0
Contains images:
Yes
Number of references:
199
Number of pages:
80
File:
File access is restricted only to the intranet of UoA.

Vasilopoulou Mavra MSc.pdf
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