Thrombosis and Thrombocytopenia after ChAdOx1 nCoV-19 Vaccination - Θρόμβωση και θρομβοπενία μετά τον εμβολιασμό ChAdOx1 nCoV-19

Nina H. Schultz, M.D., Ph.D., 

Ingvild H. Sørvoll, M.D., 

Annika E. Michelsen, Ph.D., 

Ludvig A. Munthe, M.D., Ph.D., 

Fridtjof Lund-Johansen, M.D., Ph.D., 

Maria T. Ahlen, Ph.D., 

Markus Wiedmann, M.D., Ph.D., 

Anne-Hege Aamodt, M.D., Ph.D., 

Thor H. Skattør, M.D., 

Geir E. Tjønnfjord, M.D., Ph.D., 

and Pål A. Holme, M.D., Ph.D.

https://www.nejm.org/doi/full/10.1056/NEJMoa2104882?query=featured_home%C2%BB

We report findings in five patients who presented with venous thrombosis and thrombocytopenia 7 to 10 days after receiving the first dose of the ChAdOx1 nCoV-19 adenoviral vector vaccine against coronavirus disease 2019 (Covid-19). The patients were health care workers who were 32 to 54 years of age. All the patients had high levels of antibodies to platelet factor 4–polyanion complexes; however, they had had no previous exposure to heparin. Because the five cases occurred in a population of more than 130,000 vaccinated persons, we propose that they represent a rare vaccine-related variant of spontaneous heparin-induced thrombocytopenia that we refer to as vaccine-induced immune thrombotic thrombocytopenia.

The European Medicines Agency has approved five vaccines against coronavirus disease 2019 (Covid-19), and more than 600 million doses have been administered globally.1 In Norway, older adults living in institutional settings and health care professionals who are in close contact with patients with Covid-19 have been prioritized to receive the BNT162b2 mRNA Covid-19 vaccine (Pfizer–BioNTech). In addition, the ChAdOx1 nCoV-19 vaccine (AstraZeneca) has been administered to health care professionals younger than 65 years of age who do not have close contact with patients with Covid-19. As of March 20, 2021, when administration of the vaccine was paused, a total of 132,686 persons in Norway had received the first dose of the ChAdOx1 nCoV-19 vaccine and none had received the second dose.2

Within 10 days after receiving a first immunization with ChAdOx1 nCoV-19, five health care workers 32 to 54 years of age presented with thrombosis in unusual sites and severe thrombocytopenia. Four of the patients had major cerebral hemorrhage. Here we describe this vaccine-induced syndrome of severe thrombosis and thrombocytopenia found among these five patients admitted to Oslo University Hospital. . . .