Multisystem inflammatory syndrome in children (MIS-C); atypical Kawasaki disease (KD); This is a literature report from License Party for the following literature source(s).  A 16-year-old male patient received BNT162b2 (BNT162B2), in 2022 as dose 3 (booster), single (Batch/Lot number: unknown) for covid-19 immunisation. The patient's relevant medical history included: "mild Asthma" (unspecified if ongoing). The patient's concomitant medications were not reported. Vaccination history included: Bnt162b2 (DOSE 1, SINGLE), for Covid-19 Immunization; Bnt162b2 (DOSE 2, SINGLE), for Covid-19 Immunization. The following information was reported: MULTISYSTEM INFLAMMATORY SYNDROME IN CHILDREN (hospitalization, medically significant) with onset 2022, outcome "recovering", described as "Multisystem inflammatory syndrome in children (MIS-C)"; KAWASAKI'S DISEASE (hospitalization, medically significant) with onset 2022, outcome "recovering", described as "atypical Kawasaki disease (KD)". The patient underwent the following laboratory tests and procedures: Alanine aminotransferase (8-36): (unspecified date) 60 IU/l; Blood albumin (3.1-4.8): (unspecified date) 3.0 g/dl; Blood culture: (2022) no growth after five days; Blood fibrinogen (150-480): (unspecified date) 820 mg/dl; Blood sodium (135-145): (unspecified date) 131 mEq/l; C-reactive protein (0-10.0): (unspecified date) 281.38 mg/l; Cytomegalovirus test: (2022) IgG of 7.7; Echocardiogram: (2022) inconspicuous, notes: not reveal any effusion, decreased ejection fraction, right heart strain, or ectasia or aneurysm of the visualized coronary arteries; Electrocardiogram: (2022) normal; Epstein-Barr virus antibody: (2022) negative; Fibrin D dimer (0-300): (unspecified date) 608 ng/ml; Influenza A virus test: (2022) negative; Influenza B virus test: (2022) negative; Lymphocyte count (1.0-4.0): (unspecified date) 0.5 x10 9/l; Neutrophil count (1.8-8.0): (unspecified date) 16.9 x10 9/l; Red blood cell sedimentation rate (0-15): (unspecified date) 106, notes: mm/h; Respiratory viral panel: (2022) negative; SARS-CoV-2 antibody test: (2022) pathologic, notes: anti-N-protein IgG 4.67 (positive), anti-S-protein IgM 1.04 (positive), and anti-RBD IgG more than 25,000 AU/mL (positive); SARS-CoV-2 test: (2022) negative; Serum ferritin (22-322): (unspecified date) 541 ng/ml; Streptococcus test: (2022) positive; White blood cell count (3.5-11): (unspecified date) 19.2 x10 9/l. Therapeutic measures were taken as a result of multisystem inflammatory syndrome in children (MIS-C), kawasaki's disease (KD).  Clinical course: The patient is a 16-year-old male with a past medical history of mild asthma who presented to the emergency department with six days of subjective fever, initially associated with diffuse myalgias, headaches, and fatigue. He developed limbal-sparing conjunctivitis, abdominal pain, nausea, post-prandial non-bloody nonbilious emesis, and anorexia. He had erythema of the oral mucosa and tongue with prominence of the lingual papillae, commonly described as the "strawberry-tongue" phenomenon. He did not have erythema, edema, or desquamation of the distal extremities; a rash anywhere on the body; oropharyngeal erythema, edema or exudates; or cervical lymphadenopathy. He denied sore throat, cough, dyspnea, diarrhea, dysuria, urinary urgency or frequency, focal pain, or edema. He denied weight loss, night sweats, or chills. Polymerase chain reaction (PCR) tests of nasopharyngeal swabs for SARS-CoV-2, influenza-A, and influenza-B were negative prior to his presentation to the emergency department. His parents were both symptomatic and his mother tested positive for SARS-CoV-2 by PCR 36 days prior to his symptom onset. The patient never experienced COVID-19 symptoms before or after this exposure and did not take a SARS-CoV-2 PCR test at that time. He was attending high school in person daily and was employed at a drugstore in the weeks preceding his presentation. Of note, the patient had completed a two-dose series of the BNT162b2 (Pfizer-BioNTech) vaccine approximately 34 weeks prior to presentation and 28 weeks prior to his mother's positive PCR tests. In addition, he received a third booster dose of the vaccine two weeks after the known exposure, three weeks prior to symptom onset. He was otherwise up to date on his vaccinations. After arriving at the emergency department, the patient became tachycardic and hypotensive, and his shock physiology resolved with three 1-liter boluses of normal saline. Initial laboratory workup at that time revealed leukocytosis with lymphopenia, elevated ESR, CRP, ferritin, d-dimer, fibrinogen, low serum sodium, normal BNP, and troponin. Group-A streptococcus PCR of a throat swab was positive, and he was deemed to be an asymptomatic colonized individual. A nasopharyngeal swab PCR panel for 22 common upper respiratory viruses, including SARS-CoV-2, was negative. A blood culture showed no growth after five days. A SARS-CoV-2 antibody panel was notable for: anti-Nprotein IgG 4.67 (positive), anti-S-protein IgM 1.04 (positive), and anti-RBD IgG  more than 25,000 AU/mL (positive). A CMV antibody panel was only notable for an IgG of 7.7, and EBV antibodies were negative. Point-of-care and formal echocardiograms did not reveal any effusion, decreased ejection fraction, right heart strain, or ectasia or aneurysm of the visualized coronary arteries. He had a normal electrocardiogram. He was diagnosed with MIS-C and received 2g/kg IVIG once, methylprednisolone 30mg twice daily, and enoxaparin twice daily. Following initiation of therapy, he demonstrated clinical improvement with resolution of exam findings. He was discharged in good condition with a prednisone taper, low-dose aspirin, and a final diagnosis of MIS-C with atypical KD features in a fully vaccinated adolescent.  No follow-up attempts are possible; information about lot/batch number cannot be obtained. No further information is expected.  SUSPECT PRODUCT is under agreement with BIONTECH SE.; Sender's Comments: Based on the information provided, and a temporal association, a causal association between reported events and suspect BNT162B2 cannot be excluded. 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.