Haemophagocytic lymphohistiocytosis; Anaemia; Elevated transaminases; Hyperferritinaemia; This is a literature report.  A 32-year-old female patient received BNT162b2 (BNT162B2), as dose 1, single (Batch/Lot number: unknown) and as dose 2, single (Batch/Lot number: unknown) for covid-19 immunisation. The patient's relevant medical history included: "Splenomegaly" (unspecified if ongoing), notes: outside imaging unavailable; "hospitalized" (unspecified if ongoing), notes: at an outside hospital. The patient's concomitant medications were not reported. Past drug history included: Methylprednisolone sodium succinate for Haemophagocytic lymphohistiocytosis, reaction(s): "drug ineffective", notes: 1000mg x 2 doses. The following information was reported: HAEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS (hospitalization, medically significant, life threatening), outcome "recovering"; ANAEMIA (hospitalization, medically significant), outcome "unknown"; TRANSAMINASES INCREASED (hospitalization, medically significant), outcome "unknown", described as "Elevated transaminases"; HYPERFERRITINAEMIA (hospitalization, medically significant), outcome "unknown". The event "haemophagocytic lymphohistiocytosis" required emergency room visit. The patient underwent the following laboratory tests and procedures: Antinuclear antibody: Negative; Aspergillus test: Negative; Bacterial test: Negative; Biopsy: Negative; Biopsy bone marrow: Negative; Biopsy lymph gland: Negative; BK polyomavirus test: Negative; Blood fibrinogen: 118 mg/dl; 118 mg/dl; Blood iron: 35000 ng/ml; Blood triglycerides: 527 ng/ml; Body temperature: 40 Centigrade; 40.8 Centigrade, notes: Tmax; Brucella test: Negative; Computerised tomogram abdomen: Negative; Computerised tomogram pelvis: Negative; Computerised tomogram thorax: Negative; Cryptococcus test: Negative; Culture: Negative; Cytomegalovirus test: Negative; Ehrlichia test: Negative; Epstein-Barr virus test: Negative; Flow cytometry: Negative; Haemoglobin: 80 g/l; 74 g/l; 68 g/l, notes: nadir; Hepatitis A virus test: Negative; Hepatitis B virus test: Negative; Hepatitis C virus test: Negative; Herpes virus test: Negative; HIV test: Negative; Interleukin level: 14130.2 pg/mL; histoplasmosis: Negative; Negative; Negative; neopterin (normal high range < 2.5): 9.5 ng/ml; Negative; Negative; Negative; Negative, notes: (ANA, anti-Smith Ab, anti dsDNA Ab, C3, C4); Negative; Bartonellosis: Negative; CXCL9: 16347 pg/mL; Negative; Negative; Negative; Negative; Legionella test: Negative; Leptospira test: Negative; Lumbar puncture: Negative, notes: (flow cytometry and cytopathology); Neutrophil count: 8.25, notes: k/uL; Parasite blood test: Negative; Parvovirus B19 test: Negative; Platelet count: 79, notes: k/ul; 64, notes: nadir, k/ul; Rheumatological examination: Negative; SARS-CoV-2 test: Negative; Serum ferritin (15-150): 68212 ng/ml; Transaminases: elevated; West Nile virus test: Negative. Therapeutic measures were taken as a result of haemophagocytic lymphohistiocytosis.  No follow-up attempts are possible; information about lot/batch number cannot be obtained. No further information is expected.; Sender's Comments: Based on the current limited available information, a possible contributory role of the suspect product BNT162B2 to the development of events haemophagocytic lymphohistiocytosis, anaemia, transaminases increased and hyperferritinaemia cannot be 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.,Linked Report(s) : US-PFIZER INC-202200608725 Same article/ drug/event and different patient