q9 Quebec confirms 9th case of vaccine-induced blood clot Patient is recovering at home A ninth Quebecer has suffered from vaccine-induced immune thrombotic thrombocytopenia, a rare blood-clotting syndrome, after receiving their first dose of the AstraZeneca-Oxford vaccine, the province's Health Ministry announced Tuesday. Approximately one in 50,000 people receiving their first shot may get a blood clot, the ministry says.