This literature-non-study case was reported in a literature article and describes the occurrence of COAGULATION FACTOR DEFICIENCY (Acquired factor inhibitor deficiency) and CEREBRAL HAEMORRHAGE (Presented with new onset headache and noted to have large right sub insular acute intra parenchymal hemorrhage) in an 83-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. LITERATURE REFERENCE: "PRIVATE". A case series of acquired factor inhibitor following Sars-COV2-vaccination. Blood. 2021;138(1):4244. The patient's past medical history included Arrhythmia, Coronary artery disease and Coronary arterial stent insertion. Concurrent medical conditions included Hypertension. On an unknown date, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On an unknown date, the patient experienced COAGULATION FACTOR DEFICIENCY (Acquired factor inhibitor deficiency) (seriousness criterion hospitalization) and CEREBRAL HAEMORRHAGE (Presented with new onset headache and noted to have large right sub insular acute intra parenchymal hemorrhage) (seriousness criteria hospitalization and medically significant). The patient was treated with RITUXIMAB for Adverse event, at an unspecified dose and frequency; PREDNISONE for Adverse event, at an unspecified dose and frequency; CYCLOPHOSPHAMIDE for Adverse event, at an unspecified dose and frequency and Rehabilitation therapy for Coagulation factor deficiency. At the time of the report, COAGULATION FACTOR DEFICIENCY (Acquired factor inhibitor deficiency) and CEREBRAL HAEMORRHAGE (Presented with new onset headache and noted to have large right sub insular acute intra parenchymal hemorrhage) was resolving. Related. DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, Activated partial thromboplastin time: prolonged aptt of 70 (High) prolonged APTT of 70 on Initial admission. On an unknown date, Coagulation factor IX level: 8% (Low) 8%. On an unknown date, Coagulation factor XI level: 2.4% (Low) 2.4%. On an unknown date, Imaging procedure: slightly expanded size of a parenchymal hemorrhage (abnormal) Showed slightly expanded size of a parenchymal hemorrhage centered in the right sub insular region and increasing surrounding edema with new tiny right frontal cortical parenchymal hemorrhage. On an unknown date, Prothrombin time: normal (normal) Normal on Initial admission and prolonged to 17 (High) After readmission from rehab: PT became prolonged to 17. For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter considered COAGULATION FACTOR DEFICIENCY (Acquired factor inhibitor deficiency) and CEREBRAL HAEMORRHAGE (Presented with new onset headache and noted to have large right sub insular acute intra parenchymal hemorrhage) to be related. Concomitant medications were not reported. The patient received the second dose of Moderna Covid vaccine one month prior to presentation to the hospital. Presented with new onset headache and noted to have large right sub insular acute intra parenchymal hemorrhage. Patient was managed conservatively, and that bleed was attributed to h/o hypertension. Post treatment was discharged to rehab, where the patient had worsening neurological status. After readmission from rehab: PTT remained elevated to 70 and PT became prolonged to 17. Bethesda titer was positive at 11 BU to specific to factor IX. APTT mixing studies demonstrated only partial correction of PT and no correction of APTT. The only possible etiology had been his age and patient had received SARS COV2 Moderna vaccine. Company comment: This literature-non-study case concerns an 83-year-old male patient, with medical history of Arrhythmia, Coronary artery disease and Coronary arterial stent insertion, who experienced the unexpected serious (hospitalization) events of Coagulation Factor Deficiency and Cerebral hemorrhage, which occurred approximately one month after receiving the second dose of mRNA vaccine. Patient presented with new onset headache and noted to have large right sub insular acute intra parenchymal hemorrhage. Patient was managed conservatively, and that bleed was attributed to hypertension. Post treatment (RITUXIMAB, PREDNISONE and CYCLOPHOSPHAMIDE) was discharged to Rehabilitation therapy, where the patient had worsening neurological status. Initial admission labs reveled a prolonged APTT of 70 and PT normal. After his readmission from rehab, his PTT remained elevated to 70 and PT became prolonged to 17. The mentioned medical history remains as a confounder for event cerebral haemorrahge. Age remains a confounder for event Coagulation Factor Deficiency. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report. This case was linked to MOD-2022-512334 (Patient Link). Sender's Comments: This literature-non-study case concerns an 83-year-old male patient, with medical history of Arrhythmia, Coronary artery disease and Coronary arterial stent insertion, who experienced the unexpected serious (hospitalization) events of Coagulation Factor Deficiency and Cerebral hemorrhage, which occurred approximately one month after receiving the second dose of mRNA vaccine. Patient presented with new onset headache and noted to have large right sub insular acute intra parenchymal hemorrhage. Patient was managed conservatively, and that bleed was attributed to hypertension. Post treatment (RITUXIMAB, PREDNISONE and CYCLOPHOSPHAMIDE) was discharged to Rehabilitation therapy, where the patient had worsening neurological status. Initial admission labs reveled a prolonged APTT of 70 and PT normal. After his readmission from rehab, his PTT remained elevated to 70 and PT became prolonged to 17. All factor levels were normal except Factor IX low at 8% and Factor XI low at 2.4%. The mentioned medical history remains as a confounder for event cerebral hemorrhage. Age remains a confounder for event Coagulation Factor Deficiency. The benefit-risk relationship of mRNA-1273 vaccine is not affected by this report.