Large vessel thrombosis with thrombocytopenia and disseminated intravascular coagulation (DIC) has occurred in an extremely small proportion of cases (in the order of one event per at least one million vaccinations) following SARS-CoV-2 vaccination. These cases have been observed only with the adenoviral vector Covid-19 vaccines and are similar to heparin-induced thrombosis with the appearance of autoantibodies cross-reacting with certain platelet factor 4 tests. The phenomenon has been termed "vaccine-induced thrombocytopenic thrombosis" (VITT). The question of the referral concerns the safety for the recipient of grafts (organs and tissues) which would be taken from patients who have died of thrombosis in a context of recent vaccination against SARS-CoV-2 by adenoviral vector vaccine (Astra-Zeneca vaccine and Janssen vaccine for vaccines currently authorised in France). Consideration has also been extended to live haematopoietic cell donors in this same vaccination context.
The High Council for Public Health (HCSP) has taken into account:
- the rarity of TTIV within all cases of brain death occurring in a context of thrombosis;
- the possibility of suspecting this type of complication based on the combination of the notion of recent vaccination with an adenoviral vector Covid-19 vaccine and the disturbance of simple coagulation tests;
- the benefit-risk ratio in the recipient of the transplant of organs and tissues removed in this context;
- and the need to maintain the activity of organ, tissue and cell transplantation.
The HCSP recommends:
- for deceased donors recently vaccinated with an adenoviral vector Covid-19 vaccine combining brain death, acute thrombosis and thrombocytopenia:
- to maintain the transplant if the organs are functional and if the haemostasis work-up does not show DIC;
- to discuss the indication for transplantation on a case-by-case basis in the presence of functional organs and compensated DIC, and then to ensure a reinforced follow-up of the recipient;
- to contraindicate transplantation in the case of multi-organ failure OR of active, uncompensated DIC at the time of transplantation.
- for living donors :
- not to contraindicate transplantation in a healthy donor with a stable haemostasis profile;
- not to reject a vaccinated donor if an urgent indication for transplantation is given;
- to postpone Covid-19 vaccination with an adenoviral vector vaccine in a subject recruited for donation, or to propose an mRNA vaccine.