Severe Aplastic Anemia After Receiving SARS-CoV-2 Moderna mRNA Vaccination.

A 60-year-old male patient presented to the emergency department with complaints of easy bruising and worsening epistaxis after receiving severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Moderna mRNA vaccination. He had no personal or family history of hematological conditions. He had bruises in various stages involving the upper and lower extremities. Laboratory data revealed white blood cell count of 1.2 ×103/mm3, hemoglobin of 8.0 g/dL, platelet count of 1 ×103/mm3, immature platelet fraction of 0.7%, absolute neutrophil count of 0 ×103/µL, lymphocytes of 1.1 ×103/µL, neutrophils of 3% and lymphocytes of 93%. He had normal liver and renal function tests. Bone marrow biopsy confirmed very severe aplastic anemia with severely hypocellular bone marrow. His platelets continued to downtrend despite platelet transfusions and steroids. He was treated with immunosuppressive therapy with cyclosporine, anti-thymocyte globulin, eltrombopag and prednisone. The patient was discharged but was readmitted to the hospital secondary to recurrent neutropenic fever and pneumonia. He had high-grade vancomycin-resistant enterococcal infection and Clostridium difficile infection leading to septic shock and succumbing to cardiac arrest. This case demonstrates the possibility of very severe aplastic anemia following SARS-CoV-2 mRNA vaccination and clinicians need to be aware of this rare but serious side effect.