multisystem inflammatory syndrome; This is a literature report for the following literature source(s):   A 14-year-old female patient received BNT162b2 (BNT162B2), as dose 2, single (Batch/Lot number: unknown) for covid-19 immunisation. The patient's relevant medical history and concomitant medications were not reported. Vaccination history included: Bnt162b2 (DOSE 1, SINGLE), for COVID-19 immunisation. The following information was reported: MULTISYSTEM INFLAMMATORY SYNDROME (hospitalization, medically significant), outcome "recovered". The event "multisystem inflammatory syndrome" required emergency room visit. The patient underwent the following laboratory tests and procedures: Activated partial thromboplastin time: 28.9 seconds, notes: Hospitalization for MIS-C HD1; 31.3 seconds, notes: Hospitalization for MIS-C HD3; below 20.5, notes: Pre-MIS-C hospitalization HD1; Blood albumin: 3.6 g/dl, notes: Hospitalization for MIS-C HD1; below 2.6, notes: Hospitalization for MIS-C HD3 decreased outside of reference range; 3.0 g/dl, notes: Hospitalization for MIS-C HD5; below 3.1, notes: Hospitalization for MIS-C HD7 decreased outside of reference range; below 3.1, notes: Hospitalization for MIS-C HD9 decreased outside of reference range; Blood creatinine: above 1.0, notes: HD1; above 2.2, notes: HD3; above 3.9, notes: HD5; above 2.3, notes: HD7; above 1.3, notes: HD9; Blood fibrinogen: 413 mg/dl, notes: HD1; Chest X-ray: unremarkable; Computerised tomogram: unremarkable; C-reactive protein: 17 mg/l, notes: HD1 Elevated; 47 mg/l, notes: HD3 elevated; 56 mg/l, notes: HD5 elevated; 19 mg/l, notes: HD7 elevated; 10 mg/l, notes: HD9 elevated; Electrocardiogram: normal; Fibrin D dimer: 2.8 ug/ml, notes: Elevated HD1; Influenza virus test: Negative, notes: On day 3; Liver function test: elevated; N-terminal prohormone brain natriuretic peptide: normal; N-terminal prohormone brain natriuretic peptide: 85 pg/mL, notes: HD1; 3190 pg/mL, notes: HD3 elevated; 3360 pg/mL, notes: HD5 elevated; 1300 pg/mL, notes: HD7 elevated; 1590 pg/mL, notes: HD9 elevated; Prothrombin time: 13.5 seconds, notes: HD1; 14.7 seconds, notes: HD3; SARS-CoV-2 test: Negative, notes: On day 3; Positive; Positive, notes: nucleocapsid IgG; Troponin: less than 0.02; White blood cell count: 7.8 x10^9 cells/L, notes: HD1; 5.8 x10^9 cells/L, notes: HD3; below 2.9 x10^9 cells/L, notes: HD5; 5.4 x10^9 cells/L, notes: HD7; 9.0 x10^9 cells/L, notes: HD9. Therapeutic measures were taken as a result of multisystem inflammatory syndrome. In this case, fever and fatigue, followed by congestion, cough, myalgias, headache, nausea, and vomiting, developed in an otherwise healthy 14-year-old girl (day 1 of illness). On day 3, rapid SARS-CoV-2 and influenza test results were negative. On day 12, she was brought to the emergency department for persistent fever, headache, cough, and vomiting. Three months before her illness, she had completed the 2-dose Pfizer-BioNTech COVID-19 vaccine series. Results from computed tomography of her head and chest radiograph were unremarkable. SARS-CoV-2 PCR was positive. She was prescribed amoxicillin for possible sinusitis and discharged. On day 14, she returned to the hospital for dyspnea and required low-flow oxygen for hypoxemia. Electrocardiogram, troponin, and NT-proBNP test results were normal. She was admitted and received 1 dose of remdesivir, which we discontinued because of elevated liver function test results, and 2 doses of dexamethasone; we also discontinued amoxicillin. She improved and was discharged on day 18. However, she returned the next day with recrudescent fever, emesis, and new diffuse rash, including on her palms and soles. Laboratory testing demonstrated elevated CRP, D-dimer, liver function, NT-proBNP, and creatinine levels. Abdominal ultrasound and computed tomography showed incidentally enlarged kidneys. The author empirically started clindamycin and ceftriaxone treatment and readmitted her. At readmission on day 19, differential diagnoses included MIS-C, acute COVID-19 with hyperinflammation, sepsis, toxic shock syndrome, drug reaction, and vasculitis or other autoimmune disease. Echocardiogram results were unremarkable. A SARS-CoV-2 nucleocapsid IgG test was positive. Additional infectious and rheumatologic test results were negative. After discussion among multidisciplinary specialists, the author considered MIS-C most likely, with a suspicion that her earlier symptoms might have resulted from acute COVID-19, which evolved over 3 weeks into MIS-C. We discontinued antibiotics. On day 4 of her second hospitalization, she received intravenous immunoglobulin and methylprednisolone. Her fever quickly subsided, signs and symptoms resolved, and laboratory results improved. On hospitalization day 9, she was discharged with an oral prednisone taper. Infectious disease follow-up 3 weeks after discharge revealed mild fatigue and headaches but normalized laboratory results. Cardiology follow-up through 12 weeks after discharge indicated fatigue, but echocardiogram and exercise stress testing results were unremarkable.; Sender's Comments: Based on known drug safety profile, there is reasonable possibility of causal association between the event MULTISYSTEM INFLAMMATORY SYNDROME and BNT162B2.  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.