Worsening Abdominal Pain; Fever of 102F; Pancytopenia; Myelodysplastic syndrome; This is a literature report for the following literature source(s).  A 64-year-old male patient received COVID-19 Vaccine - Manufacturer Unknown, in Mar2021 as dose 1, single (Batch/Lot number: unknown, Expiry date: Unknown) for covid-19 immunisation; piperacillin, tazobactam (ZOSYN), since 2021, intravenous for evidence based treatment. The patient's relevant medical history included: "chronic obstructive pulmonary disease" (unspecified if ongoing). The patient took concomitant medications. The following information was reported: PYREXIA (hospitalization) with onset Mar2021, outcome "unknown", described as "Fever of 102F"; ABDOMINAL PAIN (hospitalization) with onset Mar2021, outcome "unknown", described as "Worsening Abdominal Pain"; MYELODYSPLASTIC SYNDROME (hospitalization, medically significant, life threatening) with onset 2021, outcome "unknown"; PANCYTOPENIA (hospitalization, medically significant, life threatening) with onset 2021, outcome "recovering". The patient was hospitalized for pancytopenia, myelodysplastic syndrome (start date: 2021); for abdominal pain, pyrexia (start date: Mar2021). The patient underwent the following laboratory tests and procedures: Activated partial thromboplastin time: (2021) 37 seconds, notes: elevated; Amylase: (2021) Unknown results, notes: obtained on presentation; (2021) all remained unremarkable; Band neutrophil count: (2021) 19 %; Biopsy: (2021) demonstrated a tubular adenoma in the descending, notes: colon and tubule-villous adenoma of the sigmoid colon; Biopsy bone marrow: (2021) shown myelodysplastic syndrome; Blood creatinine: (2021) 1.19 mg/dl; Blood culture: (2021) Unknown results; (2021) remained unremarkable; Blood fibrinogen: (2021) 860 mg/dl, notes: elevated; Blood folate: (2021) within normal limits; Blood iron: (2021) 29 ug/L; Blood iron: (2021) demonstrated an elevated ferritin of 970 mcg/L, notes: iron of 29 ug/dl, and total iron-binding capacity of 202 ug/dl; Blood smear test: (2021) demonstrating macrocytosis, monocytosis, and few, notes: immature myeloid cells; Blood test: (2021) Unknown results, notes: obtained on presentation; (2021) all remained unremarkable; (2021) positive fecal occult; Blood urea: (2021) 16 mg/dl; Body temperature: (2021) 102 Fahrenheit; Coagulation test: (2021) demonstrated an elevated partial thromboplastin, notes: time (PTT) of 37 s, elevated fibrinogen of 860 mg/dl, and an elevated D-dimer of 6.54 mcg/mL with a normal international normalized ratio (INR) of 1.17 and prothrombin time (PT) of 12.4 s; Colonoscopy: (2021) patient's anemia and leukopenia remained unchanged, notes: patient's anemia and leukopenia remained unchanged, but his thrombocytopenia continued to worsen and reached a nadir platelet count of 37X109/L; Computerised tomogram abdomen: (2021) demonstrated a narrowing of the colon at the area, notes: of the splenic flexure concerning for a neoplastic or infectious process; Computerised tomogram pelvis: (2021) demonstrated a narrowing of the colon at the area, notes: of the splenic flexure concerning for a neoplastic or infectious process; Culture stool: (2021) Unknown results, notes: obtained on presentation; (2021) all remained unremarkable; Culture urine: (2021) Unknown results; (2021) remained unremarkable; Endoscopy: (2021) revealed two polyps, one 5 mm polyp in the, notes: descending colon and a 10 mm pedunculated polyp approximately 15 cm from the anal verge; Fibrin D dimer: (2021) 6.54 ug/ml, notes: elevated; Gastrointestinal examination: (2021) Unknown results; Haemoglobin: (2021) 8.2 g/dl, notes: persistent macrocytic anemia; (2021) 10.4 g/dl; (2021) 8.2 g/dl; (2021) 7.5 g/dl; Haptoglobin: (2021) 446 mg/dl, notes: elevated; International normalised ratio: (2021) 1.17, notes: normal; Iron binding capacity total: (2021) 202 ug/dL; Lactic acidosis: (2021) 4.49 mmol/L; Lipase: (2021) 47 IU/l; Lymphocyte count: (2021) 52 %; (2021) 40 %; Lymphocyte morphology abnormal: (2021) 3 %; Mean cell volume: (2021) 104.1, notes: fl; (2021) 104.1; Monocyte count: (2021) 1 %; (2021) 21 %; Neutrophil count: (2021) 38 %; (2021) 13 %; Platelet count: (2021) 37 x10 9/l; (2021) 74 x10 9/l, notes: thrombocytopenia; (2021) 147 x10 9/l; (2021) 78 x10 9/l; Prothrombin time: (2021) 12.4 seconds; Red blood cell sedimentation rate: (2021) 124, notes: mm/h elevated; Reticulocyte count: (2021) 0.4 x10 9/l; Serum ferritin: (2021) 970 ug/L, notes: elevated; Vitamin B12: (2021) within normal limits; White blood cell count: (2021) 3.7 x10 9/l; (2021) 7.6 x10 9/l; (2021) 2.5 x10 9/l. The action taken for piperacillin, tazobactam was unknown. Therapeutic measures were taken as a result of pancytopenia, myelodysplastic syndrome. The following death information was reported, despite no fatal outcome. The patient date of death was unknown. Reported cause of death: "passed away from complications of his pneumonia". It was not reported if an autopsy was performed.  No follow-up attempts are possible; information about lot/batch number cannot be obtained. No further information is expected.; Sender's Comments: As there is limited information in the case provided, the causal association between the events and the suspect drug cannot be excluded. The case will be reassessed once new information is available. The impact of this report on the benefit/risk profile of the Pfizer drug 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.; Reported Cause(s) of Death: passed away from complications of his pneumonia