Summary

• A combination of thrombosis and thrombocytopenia, in some cases accompanied by bleeding, has been observed very rarely following vaccination with COVID-19 Vaccine Janssen. A causal relationship with the vaccine is considered plausible. 
• These cases occurred within the first three weeks following vaccination, and mostly in women under 60 years of age.
• No specific risk factors have been identified at this stage.
• Healthcare professionals should be alert to the signs and symptoms of thromboembolism and/or thrombocytopenia.
• Those being vaccinated should be instructed to seek immediate medical attention if they develop symptoms of thromboembolism and, or thrombocytopenia following vaccination.
• Thrombosis in combination with thrombocytopenia requires specialised clinical management.  Consult applicable guidance and/or specialists (e.g., haematologists, specialists in coagulation) to diagnose and treat this condition.