This is a literature report for the following literature source(s): "Bone Marrow Suppression Secondary to the COVID-19 Booster Vaccine: A Case Report", Journal of Blood Medicine, 2022; Vol:13, pgs:69-74, DOI:10.2147/JBM.S350290. Authors report a 74-year-old male who developed bone marrow suppression and pancytopenia recorded seven days after receiving the Pfizer SARS-CoV-2 vaccine. During his hospital stay, the patient's hemoglobin, white blood cell, and platelet levels continued to trend downwards. However, all three levels showed improvement one week after discharge without robust intervention. A 74-year-old male with a history of Polychondritis and hypothyroidism presented to the hospital after falling out of his chair and inability to ambulate. The patient was found to be mildly confused upon arrival to the emergency room, limiting their ability to obtain a full verbal history. Chart review revealed the patient had received his third Pfizer Covid vaccine shot seven days before admission followed by fatigue, decreased appetite, fever, and chills. The patient had received the second Pfizer Covid-19 shot nine months before the booster. No reactions to the previous two shots were noted. Upon initial evaluation, vital signs were within normal limits and a physical exam revealed significant tenderness in the upper arm and no gross bleeding (The patient's upper arm showed erythema with no gross bleeding near the injection site). Computed tomography (CT) imaging (The patient's CT imaging of the thoracic region showed enhancement of the left axillary lymph node) was significant for enhancement of the left axillary lymph node. The patient's initial complete blood count (CBC) was remarkable for a hemoglobin count of 9.9 g/dl and platelet count of 84 x 10 9/L; both values lower than his prior hemoglobin count of 13.7 g/dl and platelet count of 180 x 10 9/L from December of 2020. His mean corpuscular volume (MCV) was elevated at 101.3 femtolitres from his prior MCV value of 95.8 femtolitres in December of 2020. His white blood cell (WBC) count was recorded at 7.6 x 10 9/L. The hemoglobin, WBC, and platelet count further down trended from his baseline. Anemia labs including ferritin levels (554 ng/mL), vitamin B12 (253 pg/mL), total bilirubin (0.5 mg/dL), and reticulocyte count (0.8%) were nonsignificant during the patient's hospital stay. The patient's left shoulder presented with extensive bruising, erythema, papular rash, warmth, and tenderness on palpation during the hospitalization. An improvement in WBC and platelet levels was noted on day 4 of hospitalization. Before discharge, the patient was fully alert and oriented and reported improvement in his symptoms. Examination of his lateral left arm showed decreased erythema and bruising with slight petechiae. The patient was discharged due to stabilization of labs and encouraged to take oral vitamin B12 supplements. During his outpatient follow-up six days after hospitalization, his hemoglobin increased to 10.5 g/dl, WBC count increased to 4.9 x 10 9/L, and platelets increased to 101 x 10 9/L. This case report highlights pancytopenia secondary to bone marrow suppression following Pfizer vaccination against SARS-CoV-2. It is important to consider the possibility of bone marrow suppression following the third vaccine against SARS-CoV-2. Sender's Comments: Based on available information and the drug temporal relationship, the causality between the events - Myelosuppression, Pancytopenia, and the suspect drug "BNT162B2" cannot be completely excluded. The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to regulatory authorities, Ethics Committees, and Investigators, as appropriate.